DOCSLIB.ORG

HW9 (106 Points Possible)

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
HW9 (106 Points Possible) Name: ______________________ Class: _________________ Date: _________ ID: A HW9 (106 points possible) True/False (2 points each) Indicate whether the statement is true or false. ____ 1. The atmosphere of Mars is mostly composed of carbon dioxide; therefore the greenhouse effect makes the average temperature 35 degrees warmer than it would be without its atmosphere. ____ 2. In the absence of a greenhouse effect, water on the surface of Earth would be frozen. ____ 3. Aurorae are produced only near the northern and southern magnetic poles of a planet because charged particles arriving in the solar wind cannot cross the magnetic field lines. ____ 4. Winds are generated on Earth primarily because the Sun unevenly heats our rotating planet. ____ 5. Venus’s atmospheric clouds are so thick that the surface of the planet is not seen when observing it in visible light. Multiple Choice (4 points each) Identify the choice that best completes the statement or answers the question. ____ 1. Which is NOT a reason that we suspect that the extinction of the dinosaurs was caused by a large impact by a large object? a. Many dinosaur fossils are found below the K-T boundary, but none above it. b. The material in the K-T boundary is rich in iridium. c. Soot is found in the material in the K-T boundary, which probably came from fires caused by the impact. d. An impact crater has been found near Mexico’s Yucatan Peninsula. e. The remaining meteorite has been identified on the bottom of the Gulf of Mexico. ____ 2. What is the reason Mercury has so little gas in its atmosphere? a. Its mass is small. d. Its escape velocity is low. b. It has a high temperature. e. All of the above are reasons. c. It is close to the Sun. ____ 3. Why did the terrestrial planets lose the majority of the gas in their primary atmospheres? a. They were too hot and their escape velocities too low to hold onto them. b. The solar wind was too strong and blew these gasses off the planets. c. Their high surface temperatures made the gas chemically react with the rock. d. The centrifugal force from the planets’ fast rotation rates made them fly off. e. The initial gases were so heavy when the planet differentiated that they sank to the core. 1 Name: ______________________ ID: A ____ 4. The nitrogen in the Earth’s atmosphere primarily came from: a. ammonia delivered by comet impacts b. photosynthesis done by algae and plants c. oxidation of silicate rich minerals d. rock delivered by asteroid impacts e. its primary atmosphere ____ 5. Earth has roughly _________ times more atmospheric pressure than Mars and _________ times less than Venus. a. 10; 10 d. 2; 10 b. 200; 100 e. 1,000; 200 c. 2,000; 2 ____ 6. The main greenhouse gases in the atmosphere of the terrestrial planets are: a. oxygen and nitrogen d. hydrogen and helium b. methane and ozone e. methane and ammonia c. carbon dioxide and water vapor ____ 7. Earth releases the energy it receives from the Sun by emitting _________ radiation. a. infrared d. radio b. visible e. microwave c. ultraviolet ____ 8. The greenhouse effect raises Earth’s surface temperature by roughly: a. 0 K d. 35 K b. 0.35 K e. 350 K c. 3.5 K ____ 9. If photosynthesis were to disappear on Earth: a. the atmosphere would become less dense b. oxygen would disappear from the atmosphere c. the atmosphere would become hotter d. nitrogen would disappear from the atmosphere e. the amount of water vapor in the atmosphere would decrease ____ 10. Approximately _________ years ago, _________ began producing oxygen in enough amounts to be a significant fraction in the Earth’s atmosphere. a. 100 million; trees and plants d. 2.5 billion; bacteria and algae b. 1 billion; trees and plants e. 2,000; animals and humans c. 250 million; bacteria and algae ____ 11. The shape of the Earth’s magnetosphere is modified by: a. the Moon’s tidal force d. asymmetries in the shape of Earth’s core b. the solar wind e. Earth’s elliptical orbit c. Earth’s own gravity 2 Name: ______________________ ID: A ____ 12. Hurricanes are powered by: a. Hadley circulation d. electrical conductivity of water b. the Coriolis effect e. the greenhouse effect c. the heat of vaporization of water ____ 13. Earth’s sky is blue because: a. blue light from the sun is more readily scattered by molecules in the atmosphere than red light b. of reflected light from the oceans c. red light from the sun is more readily scattered by molecules in the atmosphere than blue light d. molecules that make up the Earth’s atmosphere radiate preferentially at blue wavelengths e. the Sun radiates more blue light than other wavelengths ____ 14. Venus has an unusual rotation rate because: a. it is very slow d. it is very fast b. it is very slow and retrograde e. it is very fast and retrograde c. its obliquity is 90 degrees Short Answer (8 points each) 1. If there is water on Mars today, where is it likely to be? Name two separate pieces of evidence we have that Mars once had flowing water on its surface and how this evidence was obtained. 2. Where is most of Earth’s supply of carbon dioxide today? 3. If there are 104 kg of air above every square meter of the surface of Earth, and Earth is modeled as a sphere of radius 6.4 × 106 m, what is the mass of Earth’s atmosphere and what fraction is it of the total mass of the Earth? Show your calculation. 4. Over the last century, why has the ozone hole over the Earth grown larger? How long might it take to revert to its former state? 5. The global winds on Earth are the result of a combination of what three things? 3.
Load more

Recommended publications
  • Astronomy 201 Review 2 Answers What Is Hydrostatic Equilibrium? How Does Hydrostatic Equilibrium Maintain the Su
    Astronomy 201 Review 2 Answers What is hydrostatic equilibrium? How does hydrostatic equilibrium maintain the Sun©s stable size? Hydrostatic equilibrium, also known as gravitational equilibrium, describes a balance between gravity and pressure. Gravity works to contract while pressure works to expand. Hydrostatic equilibrium is the state where the force of gravity pulling inward is balanced by pressure pushing outward. In the core of the Sun, hydrogen is being fused into helium via nuclear fusion. This creates a large amount of energy flowing from the core which effectively creates an outward-pushing pressure. Gravity, on the other hand, is working to contract the Sun towards its center. The outward pressure of hot gas is balanced by the inward force of gravity, and not just in the core, but at every point within the Sun. What is the Sun composed of? Explain how the Sun formed from a cloud of gas. Why wasn©t the contracting cloud of gas in hydrostatic equilibrium until fusion began? The Sun is primarily composed of hydrogen (70%) and helium (28%) with the remaining mass in the form of heavier elements (2%). The Sun was formed from a collapsing cloud of interstellar gas. Gravity contracted the cloud of gas and in doing so the interior temperature of the cloud increased because the contraction converted gravitational potential energy into thermal energy (contraction leads to heating). The cloud of gas was not in hydrostatic equilibrium because although the contraction produced heat, it did not produce enough heat (pressure) to counter the gravitational collapse and the cloud continued to collapse.
    [Show full text]
  • Arxiv:2007.01446V1 [Astro-Ph.EP] 3 Jul 2020 Disk
    MNRAS 000,1{9 (2020) Preprint 6 July 2020 Compiled using MNRAS LATEX style file v3.0 Losing Oceans: The Effects of Composition on the Thermal Component of Impact-driven Atmospheric Loss John B. Biersteker1? and Hilke E. Schlichting1;2 1Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139-4307, USA 2UCLA, 595 Charles E. Young Drive East, Los Angeles, CA 90095, USA Accepted XXX. Received YYY; in original form ZZZ ABSTRACT The formation of the solar system's terrestrial planets concluded with a period of gi- ant impacts. Previous works examining the volatile loss caused by the impact shock in the moon-forming impact find atmospheric losses of at most 20{30 per cent and essentially no loss of oceans. However, giant impacts also result in thermal heating, which can lead to significant atmospheric escape via a Parker-type wind. Here we show that H2O and other high-mean molecular weight outgassed species can be effi- ciently lost through this thermal wind if present in a hydrogen-dominated atmosphere, substantially altering the final volatile inventory of terrestrial planets. Specifically, we demonstrate that a giant impact of a Mars-sized embryo with a proto-Earth can re- move several Earth oceans' worth of H2O, and other heavier volatile species, together with a primordial hydrogen-dominated atmosphere. These results may offer an expla- nation for the observed depletion in Earth's light noble gas budget and for its depleted xenon inventory, which suggest that Earth underwent significant atmospheric loss by the end of its accretion. Because planetary embryos are massive enough to accrete primordial hydrogen envelopes and because giant impacts are stochastic and occur concurrently with other early atmospheric evolutionary processes, our results suggest a wide diversity in terrestrial planet volatile budgets.
    [Show full text]
  • Lecture 21: Venus
    Lecture 21: Venus 1 Venus Terrestrial Planets Animation Venus •The orbit of Venus is almost circular, with eccentricity e = 0.0068 •The average Sun-Venus distance is 0.72 AU (108,491,000 km) •Like Mercury, Venus always appears close to the Sun in the sky Venus 0.72 AU 47o 1 AU Sun Earth 2 Venus •Venus is visible for no more than about three hours •The Earth rotates 360o in 24 hours, or o o 360 = 15 24 hr hr •Since the maximum elongation of Venus is 47o, the maximum time for the Sun to rise after Venus is 47o ∆ t = ≈ 3 hours 15o / hr Venus •The albedo of an object is the fraction of the incident light that is reflected Albedo = 0.1 for Mercury Albedo = 0.1 for Moon Albedo = 0.4 for Earth Albedo = 0.7 for Venus •Venus is the third brightest object in the sky (Sun, Moon, Venus) •It is very bright because it is Close to the Sun Fairly large (about Earth size) Highly reflective (large albedo) Venus •Where in its orbit does Venus appears brightest as viewed from Earth? •There are two competing effects: Venus appears larger when closer The phase of Venus changes along its orbit •Maximum brightness occurs at elongation angle 39o 3 Venus •Since Venus is closer to the Sun than the Earth is, it’s apparent motion can be retrograde •Transits occur when Venus passes in front of the solar disk as viewed from Earth •This happens about once every 100 years (next one is in 2004) Venus (2 hour increments) Orbit of Venus •The semi-major axis of the orbit of Venus is a = 0.72 AU Venus Sun a •Kepler’s third law relates the semi-major axis to the orbital period
    [Show full text]
  • Exoplanet Secondary Atmosphere Loss and Revival 2 3 Edwin S
    1 Exoplanet secondary atmosphere loss and revival 2 3 Edwin S. Kite1 & Megan Barnett1 4 1. University of Chicago, Chicago, IL ([email protected]). 5 6 Abstract. 7 8 The next step on the path toward another Earth is to find atmospheres similar to those of 9 Earth and Venus – high-molecular-weight (secondary) atmospheres – on rocky exoplanets. 10 Many rocky exoplanets are born with thick (> 10 kbar) H2-dominated atmospheres but 11 subsequently lose their H2; this process has no known Solar System analog. We study the 12 consequences of early loss of a thick H2 atmosphere for subsequent occurrence of a high- 13 molecular-weight atmosphere using a simple model of atmosphere evolution (including 14 atmosphere loss to space, magma ocean crystallization, and volcanic outgassing). We also 15 calculate atmosphere survival for rocky worlds that start with no H2. Our results imply that 16 most rocky exoplanets interior to the Habitable Zone that were formed with thick H2- 17 dominated atmospheres lack high-molecular-weight atmospheres today. During early 18 magma ocean crystallization, high-molecular-weight species usually do not form long-lived 19 high-molecular-weight atmospheres; instead they are lost to space alongside H2. This early 20 volatile depletion makes it more difficult for later volcanic outgassing to revive the 21 atmosphere. The transition from primary to secondary atmospheres on exoplanets is 22 difficult, especially on planets orbiting M-stars. However, atmospheres should persist on 23 worlds that start with abundant volatiles (waterworlds). Our results imply that in order to 24 find high-molecular-weight atmospheres on warm exoplanets orbiting M-stars, we should 25 target worlds that formed H2-poor, that have anomalously large radii, or which orbit less 26 active stars.
    [Show full text]
  • Astr150 Summer 2014 : Section Notes
    UNIVERSITYOF WASHINGTON,DEPARTMENT OF ASTRONOMY AND ASTROPHYSICS Astr150 Summer 2014 : section notes Chris Suberlak July 24, 2014 1 SECTION 6: ATMOSPHERIC ESCAPE In the previous section we discussed plate tectonics, which shows how the heat from initial contraction and the ensuing heat of the radioactive decay, provide energy necessary to drive plate tectonics and volcanism. Sometimes water is not present, which results in a lack of plate tectonics, but doesn’t stop volcanism - like in a case of Venusian ’blob tectonics’. Initially a planet is formed with many gases primordially present in the Solar System, such as Hydrogen and Helium - this is called the Primary Atmosphere. Such atmosphere may be quickly lost if the v 1 v . This is true because v - the gas velocity, is linked to escape È 6 g as g as temperature, as we can equate the thermal and kinetic energies of particles: mv2 k T (1.1) b Æ 2 where kb is the Boltzmann constant, T is the temperature at that distance from the Sun, m - mass of the gas molecules, and v - velocity of gas particles. From that equation a rearrangement of variables yields: s 2kbT vg as (1.2) Æ m and if we express m in atomic mass units : 1 amu = 1.66E 27 [kg], and insert kb 1.38E 23 2 2 1 ¡ Æ ¡ [m kg s¡ K ¡ ] then the constants simplify : s T vg as 157 (1.3) Æ m which is precisely the equation used in the lab. 1 This shows us that not all bodies can hold on to all types of atmospheres: the escape velocity of the Earth is v 11200 [m/s], and so we need v (1/6)11200, thus v 1866 Ear th Æ g as Ç g as Ç [m/s].
    [Show full text]
  • Exoplanet Secondary Atmosphere Loss and Revival
    Exoplanet secondary atmosphere loss and revival Edwin S. Kitea,1 and Megan N. Barnetta aDepartment of the Geophysical Sciences, University of Chicago, Chicago, IL 60637 Edited by Mark Thiemens, University of California San Diego, La Jolla, CA, and approved June 19, 2020 (received for review April 3, 2020) The next step on the path toward another Earth is to find atmo- atmosphere? Or does the light (H2-dominated) and transient pri- spheres similar to those of Earth and Venus—high–molecular- mary atmosphere drag away the higher–molecular-weight species? weight (secondary) atmospheres—on rocky exoplanets. Many rocky Getting physical insight into the transition from primary to sec- > exoplanets are born with thick ( 10 kbar) H2-dominated atmo- ondary atmospheres is particularly important for rocky exoplanets spheres but subsequently lose their H2; this process has no known that are too hot for life. Hot rocky exoplanets are the highest signal/ Solar System analog. We study the consequences of early loss of a noise rocky targets for upcoming missions such as James Webb thick H atmosphere for subsequent occurrence of a high–molecular- 2 Space Telescope (JWST) (8) and so will be the most useful for weight atmosphere using a simple model of atmosphere evolution (including atmosphere loss to space, magma ocean crystallization, and checking our understanding of this atmospheric transition process. volcanic outgassing). We also calculate atmosphere survival for rocky Secondary atmospheres are central to the exoplanet explora- tion strategy (9, 10). Previous work on the hypothesis that pri- worldsthatstartwithnoH2. Our results imply that most rocky exo- planets orbiting closer to their star than the habitable zone that were mary atmospheres played a role in forming secondary atmospheres formed with thick H2-dominated atmospheres lack high–molecular- includes that of Eucken in the 1940s (11), Urey (12), Cameron and weight atmospheres today.
    [Show full text]
  • Balick's 101 Climate Slides
    Balick’s 101 climate slides Earth’s Atmosphere • Primary atmosphere of Earth was hot. It quickly evaporated (H, He) or chemically evolved (“metals”) • Secondary atmospheres were acquired or formed later by: – Accretion (but locked in the interior). – Volcanism & comet impacts (releasing the gas from the interior). Atmospheres of other planets • Secondary atmospheres – Probably from volcanic “outgasing” – low-mass or hot environments (mercury, Moon) could withstand evaporation. Atmospheres lost. – Mars has probably lost 99% of its secondary atmosphere. Pressure 1% Earth, 0.01% of Venus. – Venus held its secondary atmosphere. Pressure 100 times Earth. Holds heat. – Earth’s secondary atmosphere is largely chemically processed into limestone by chemical reactions in water: CO2 + H2O → carbonic acid, acid reacts with calcium or potassium to make precipitating rock. Modern Atmosphere of Earth • Secondary atmospheres – Earth’s secondary atmosphere is largely chemically processed into limestone by chemical reactions in water: • CO2 + H2O → carbonic acid, acid reacts with calcium or potassium to make precipitating rock. – Plants have transformed the rest of the atmosphere, converting residual CO2 into food and oxygen. – Oxygen (a poison for plants) is used by animals for energy + CO2. – Plants/animals: “symbiosis” maintains balance of O2 and CO2 (until start of industrial revolution) Modern Atmosphere of Earth Various forms of animal life appear. Breathe O2 and respire CO2. dinosaurs ex@nct Greenhouse Effect Q: Why does your car’s interior become hot when you park in the Sun? A: Greenhouse effect. (What’s that?) Each year about 37 babies and toddlers die when they are accidentally leH strapped in car safety seats or become trapped in vehicles that rapidly heat up.
    [Show full text]
  • Earth's Earliest Atmospheres
    Downloaded from http://cshperspectives.cshlp.org/ at UNIV OF CHICAGO on February 4, 2015 - Published by Cold Spring Harbor Laboratory Press Earth’s Earliest Atmospheres Kevin Zahnle1, Laura Schaefer2, and Bruce Fegley2 1Space Science Division, NASA Ames Research Center, MS 245-3, Moffett Field, California 94035 2Planetary Chemistry Laboratory, Department of Earth and Planetary Sciences and McDonnell Center for the Space Sciences, Washington University, St Louis, Missouri 63130 Correspondence: [email protected] Earth is the one known example of an inhabited planet and to current knowledge the likeliest site of the one known origin of life. Here we discuss the origin of Earth’s atmosphere and ocean and some of the environmental conditions of the early Earth as they may relate to the origin of life. A key punctuating event in the narrative is the Moon-forming impact, partly because it made Earth for a short time absolutely uninhabitable, and partly because it sets the boundary conditions for Earth’s subsequent evolution. If life began on Earth, as opposed to having migrated here, it would have done so after the Moon-forming impact. What took place before the Moon formed determined the bulk properties of the Earth and probably determined the overall compositions and sizes of its atmospheres and oceans. What took place afterward animated these materials. One interesting consequence of the Moon-forming impact is that the mantle is devolatized, so that the volatiles subsequently fell out in a kind of condensation sequence. This ensures that the volatiles were concentrated toward the surface so that, for example, the oceans were likely salty from the start.
    [Show full text]
  • Chapter 4 : Planetary Atmospheres H. Equilibrium and Scale Height
    Chapter 4 : Planetary Atmospheres Astro 9601 4 Planetary Atmospheres: Topics to be covered • Density and Scale Height (4.1) • In equilibrium, there is a relation between pressure, density and gravity. • Thermal Structure (4.2) Force from gravity: Force from pressure: • Consider a slab with thickness = − • Observations (4.3.3) – All dz and density ρ. FG Mg Fp = (P + dP)dA − (P)dA • This slab exerts a force on the F = −ρ dA dz g = dPdA • Clouds (4.4) – All slab below it due to its mass G and gravity. • Meteorology (4.5) – All • This force, per unit area, is a For equillibrium: pressure. dP = −ρg dz • Atmospheric Escape (4.8) – All • There is a change in pressure dP across the slab due to its mass. = −ρg • Planetary Atmosphere Evolution (4.9) dz 2 5 H. Equilibrium and Scale Height • We can combine the If g and T are approx. expression for hydrostatic constant, the solution to Part I : Scale height, heat sources, equilibrium with the ideal gas this is an exponential: law to get the density as a − z / H energy transport, and thermal function of height: ρ ∝ e structure Gas law: P=nkTP = nkT kT where n is the number density. H ≈ gm Assume n ~ ρ / m m=mass per molecule Note that T and g are not P(z) ~ ρ(z)kT / m really constant with z, but it’s a useful approx. dP dρ kT = = −gρ Rearranging the equation dz dz m 3 shows that P, ρ and n all have 6 the same height dependence. 1 Scale heights for planetary atmospheres The mass of the Earth is about 1/300th that of Jupiter The radius of the Earth is about 1/10th that of Jupiter.
    [Show full text]
  • Notes for 3/26/12
    Luke Boggs, Will Abney, Matt Bestic, Paristu Alizadeh, Neal Amos, Guthrie Akins Notes for 3/26/12 The Air Pressure differences between the terrestrial planets still need to be explained. Venus’ air pressure is far higher than it should be, in comparison to Earth’s. Mars’ is much less than it should be, compared to Earth’s. The CO₂ in Earth’s atmosphere is removed, into the soil through the water. This can explain why there is less CO₂ in Earth’s atmosphere, compared with the other two planets – and it has to do with the “Goldilocks” idea that water can be liquid on Earth, but not on Venus or Mars. The rise of life on Earth got rid of the rest of the CO₂ (most of it) in their photosynthetic processes, thereby increasing the O₂ content in the atmosphere. Taking away all of the CO₂ from the atmosphere lessened the air pressure on Earth. Since it didn’t happen on Venus, the air pressure there has increased even more. This increase in CO₂ also causes the surface of Venus to reach temperatures of 800 K. What about Mars? At one point, there was liquid water (we have evidence of it), which means that there must have been higher temperatures and higher pressures. But Mars today has lost about 90% of its atmosphere, and now the only water on its surface is frozen. Since Mars is smaller than the Earth, it cooled off more quickly than Earth. As it did so, the cycle for removing the water and replenishing it broke down.
    [Show full text]
  • Mantle Redox State Drives Outgassing Chemistry and Atmospheric Composition of Rocky Planets G
    www.nature.com/scientificreports OPEN Mantle redox state drives outgassing chemistry and atmospheric composition of rocky planets G. Ortenzi1,2*, L. Noack2, F. Sohl1, C. M. Guimond2,3, J. L. Grenfell1, C. Dorn4, J. M. Schmidt2, S. Vulpius2, N. Katyal5, D. Kitzmann6 & H. Rauer1,2,5 Volcanic degassing of planetary interiors has important implications for their corresponding atmospheres. The oxidation state of rocky interiors afects the volatile partitioning during mantle melting and subsequent volatile speciation near the surface. Here we show that the mantle redox state is central to the chemical composition of atmospheres while factors such as planetary mass, thermal state, and age mainly afect the degassing rate. We further demonstrate that mantle oxygen fugacity has an efect on atmospheric thickness and that volcanic degassing is most efcient for planets between 2 and 4 Earth masses. We show that outgassing of reduced systems is dominated by strongly reduced gases such as H2 , with only smaller fractions of moderately reduced/oxidised gases (CO ,H 2O ). Overall, a reducing scenario leads to a lower atmospheric pressure at the surface and to a larger atmospheric thickness compared to an oxidised system. Atmosphere predictions based on interior redox scenarios can be compared to observations of atmospheres of rocky exoplanets, potentially broadening our knowledge on the diversity of exoplanetary redox states. Atmospheric evolution on a rocky planet is afected by numerous fundamental processes. Generally, atmospheres can be accreted from the proto-planetary disk (primordial atmosphere), or outgassed from the interior either during the cooling of a magma ocean (primary atmosphere) or by volcanism during the planet’s long-term geo- logical history (secondary atmosphere).
    [Show full text]
  • C:\Frontpage Webs\Content\Phy150fall03
    Review Lecture 10 1) The solar system was formed from gravitational collapse of an enormous gas cloud, mostly hydrogen (74%) and helium (24%), but also some heavier elements present from burned out stars. From radioactive decay dating, using very long-lived, naturally occurring, radioactive elements in the Earth’s crust 10 232 139. x 10 years 208 90Th→ 82 Pb one estimates the age of the Earth and the solar system to be 4.6 ± 1 billion years old. This can be compared to the estimated time for the gravitational accretion process to form the solar system of 100,000 years. 2) The temperature within the gaseous nebula surrounding the forming sun determined what elements coalesced out into planets. A) Refractory elements coalesced first to form Mercury, Venus, Earth, and Mars, the terrestrial planets. B) Hydrogen, helium, and methane formed the gas giants Jupiter, Saturn, Uranus, and Neptune further out . C) Pluto is a small ball of ice and rock. 1 3) The cooling rate of planets depends on the radiation emitted - . radius2 4) The primary atmosphere has been modified by gases escaping the gravitational attraction of the planets. The average velocity of an atom or molecule is given by Maxwell-Boltzmann 3kT v = . average m When this is on the order of the escape velocity from the planet the atom or molecule is lost to outer space. Thus, Earth no longer has free hydrogen in its atmosphere. A picture of the gas cloud coalescing into a star. a) A slowly rotating portion of a large nebula becomes a distinct globule and a mostly gaseous cloud collapses by gravitational attraction.
    [Show full text]