D
Green skin is common in science fiction, but what if green skin were not just for aliens? If humans had green skin, what if it granted us the ability to perform photosynthesis(光合作用),which plants use to live off of sunlight?
Let’s analyze what science says about it and ask award-winning science-fiction author John Scalzi what he thinks.
Plants can live off of photosynthesis because they grow broad, flat leaves to harvest as much light as possible. They also need less energy because they are far less active than animals.
According to Lindsay Turnbull, a plant ecologist at the University of Oxford, if the skin of a woman were photosynthetic like a leaf, the amount of surface area she had would satisfy only 1% of her daily energy requirements to survive. For a photosynthesizing woman to meet her energy demands, she would need a lot more skin — about a tennis court’s worth, Turnbull estimated.
In addition, photosynthesis requires carbon dioxide. Plants have pores(毛孔)that they use to supply the gas to their cells. If photosynthetic humans had chloroplasts(叶绿体), they might need porous skin to let in carbon dioxide, but such pores might let other things leak in or out — for instance, moisture(水分) — in ways that might prove harmful to the human body.
One might wonder if photosynthetic people might prefer moving to sunny climates. Although such people might receive a small increase from photosynthesis if they moved to a desert area, they would likely have other resource issues to deal with, such as a lack of water, Scalzi said. “There’s always going to be trade-offs(平衡),”he noted.
And would photosynthetic humans prefer little or no clothing, to absorb all those rays? In some photosynthetic societies, clothing might become a symbol of the elite — a sign they get enough energy from food and do not need photosynthesis. You can imagine them saying, “I'm rich, so I can cover up,” Scalzi said.
So, would Scalzi want photosynthetic skin for himself? “Probably not,” he said. “I don't see the benefit from it being so great that I would completely change the way I’d look to benefit from it.”
32. Why can’t humans live off of photosynthesis according to Lindsay Turnbull?
A. Because we are less active. B. Because we wear clothes.
C. Because we don’t have green skin. D. Because our skin area is not large enough.
33. If photosynthetic humans had pores, what would be the disadvantage?
A. They would absorb too much CO2.
B. They would release some useful substances.
C. They would be too small for human beings.
D. They would keep gases from entering the human body.
34. What might be the reason why Scalzi says no to photosynthetic skin for himself?
A. He was too conservative to accept that.
B. He wouldn’t like to move to sunny climates.
C. He believed there were more risks than benefits.
D. He thought clothing was simply a symbol of upper class.
35. How does the author support the theme of the text?
A. By providing research results. B. By describing a process.
C. By making classifications. D. By following the time order.
32-35 DBCA
Green skin is common in science fiction, but what if green skin were not just for aliens? If humans had green skin, what if it granted us the ability to perform photosynthesis(光合作用),which plants use to live off of sunlight?
Let’s analyze what science says about it and ask award-winning science-fiction author John Scalzi what he thinks.
Plants can live off of photosynthesis because they grow broad, flat leaves to harvest as much light as possible. They also need less energy because they are far less active than animals.
According to Lindsay Turnbull, a plant ecologist at the University of Oxford, if the skin of a woman were photosynthetic like a leaf, the amount of surface area she had would satisfy only 1% of her daily energy requirements to survive. For a photosynthesizing woman to meet her energy demands, she would need a lot more skin — about a tennis court’s worth, Turnbull estimated.
In addition, photosynthesis requires carbon dioxide. Plants have pores(毛孔)that they use to supply the gas to their cells. If photosynthetic humans had chloroplasts(叶绿体), they might need porous skin to let in carbon dioxide, but such pores might let other things leak in or out — for instance, moisture(水分) — in ways that might prove harmful to the human body.
One might wonder if photosynthetic people might prefer moving to sunny climates. Although such people might receive a small increase from photosynthesis if they moved to a desert area, they would likely have other resource issues to deal with, such as a lack of water, Scalzi said. “There’s always going to be trade-offs(平衡),”he noted.
And would photosynthetic humans prefer little or no clothing, to absorb all those rays? In some photosynthetic societies, clothing might become a symbol of the elite — a sign they get enough energy from food and do not need photosynthesis. You can imagine them saying, “I'm rich, so I can cover up,” Scalzi said.
So, would Scalzi want photosynthetic skin for himself? “Probably not,” he said. “I don't see the benefit from it being so great that I would completely change the way I’d look to benefit from it.”
32. Why can’t humans live off of photosynthesis according to Lindsay Turnbull?
A. Because we are less active. B. Because we wear clothes.
C. Because we don’t have green skin. D. Because our skin area is not large enough.
33. If photosynthetic humans had pores, what would be the disadvantage?
A. They would absorb too much CO2.
B. They would release some useful substances.
C. They would be too small for human beings.
D. They would keep gases from entering the human body.
34. What might be the reason why Scalzi says no to photosynthetic skin for himself?
A. He was too conservative to accept that.
B. He wouldn’t like to move to sunny climates.
C. He believed there were more risks than benefits.
D. He thought clothing was simply a symbol of upper class.
35. How does the author support the theme of the text?
A. By providing research results. B. By describing a process.
C. By making classifications. D. By following the time order.
32-35 DBCA
