In this task, you're given an article, a question which often contains a blank and four options (associated with "A", "B", "C", "D"). Your task is to find the correct answer (from the given options) for the question from the given article and return one of the options from "A", "B", "C", and "D". Do not generate anything else apart from one of the following characters: "A", "B", "C", "D". There is only one correct answer for each question.

[Q]: Article: Life in the Clear Transparent animals let light pass through their bodies the same way light passes through a window. These animals typically live between the surface of the ocean and a depth of about 3,300 feet--as far as most light can reach. Most of them are extremely delicate and can be damaged by a simple touch. Sonke Johnsen, a scientist in biology, says, "These animals live through their life alone. They never touch anything unless they're eating it, or unless something is eating them." And they are as clear as glass. How does an animal become see-through? It's trickier than you might think. The objects around you are visible because they interact with light. Light typically travels in a straight line. But some materials slow and scatter light, bouncing it away from its original path. Others absorb light, stopping it _ in its tracks. Both scattering and absorption make an object look different from other objects around it, so you can see it easily. But a transparent object doesn't absorb or scatter light, at least not very much, Light can pass through it without bending or stopping. That means a transparent object doesn't look very different from the surrounding air or water. You don't see it ----you see the things behind it. To become transparent, an animal needs to keep its body from absorbing or scattering light. Living materials can stop light because they contain pigments that absorb specific colors of light. But a transparent animal doesn't have pigments, so its tissues won't absorb light. According to Johnsen, avoiding absorption is actually easy. The real challenge is preventing light from scattering. Animals are built of many different materials----skin, fat, and more----and light moves through each at a different speed. Every time light moves into a material with a new speed, it bends and scatters. Transparent animals use different tricks to fight scattering. Some animals are simply very small or extremely flat. Without much tissue to scatter light, it is easier to be see--through. Others build a large, clear mass of non-living jelly-lie material and spread themselves over it . Larger transparent animals have the biggest challenge, because they have to make all the different tissues in their bodies slow down light exactly as much as water does. They need to look uniform. But how they're doing it is still unknown. One thing is clear for these larger animals, staying transparent is an active process. When they die, they turn a non-transparent milky white.
Question: One way for an animal to become transparent is to _ .
Options: (A) change the direction of light travel (B) gather materials to scatter light. (C) avoid the absorption of light (D) grow bigger to stop light.
[A]: C

[Q]: Article: One of my China Dialogue colleagues in Beijing recently bought a Philips energy-saving light bulb to replace a standard one.He was happy with his choice.It may have cost 30 yuan (just under US$4.50) - ten times the price of a filament bulb - but he wanted to save energy as part of his low-carbon lifestyle.And according to the shopkeeper, he would save, in the long run, much more than the 30 yuan he was spending. Yet only one month later, his expensive light bulb blew up, before he had saved even a small part of the purchase price.Will he stick to his high-cost, low-carbon lifestyle? China's environmental organizations have started to advocate low-carbon lifestyles and the decrease of carbon footprints to help fight against climate change.But they have overlooked one fact: in China, low-carbon living comes at a high cost.It means buying energy-saving bulbs and appliances, and environmentally friendly building materials and daily goods.Cost can no longer be the only standard for purchases.An energy-saving and environmentally friendly product is more expensive than a standard alternative - whether it's a simple light bulb or the house it shines.For average consumers, even buying an ordinary bulb is a huge burden.How can we persuade ordinary people to choose an energy-saving residence? This is not a trend they can afford to follow; perhaps this fashion is only for the rich. Most consumers today do not cause huge carbon dioxide (CO2) emissions.Their responsibility lies not in choosing a low-carbon lifestyle today, but in avoiding a high-carbon life in the future.The principle of "common but differentiated responsibility" - a basis of sustainable development - can be applied here as well. In China, low-carbon living still is resisted by a lack of social infrastructure . Even if your salary allows you to make that choice, nobody is there to help you accomplish it. Consider energy-saving homes. You need to find out whether or not the developer has used natural materials wherever possible; how effective the insulation(, ) is; and what the green credentials of installed equipment are.You can read up a little, but you'll still be lucky to avoid being puzzled by the developers' marketing.Many so-called energy-saving buildings are nothing of the sort, and some are even more energy-hungry than the average home - as Li Taige warned in his article "Energy-efficient buildings? Not always", on China Dialogue last August.
Question: What may probably be the best title of this passage?
Options: (A) To purchase a cheap bulb - your wise alternative. (B) To choose an energy-saving residence - a must of your life (C) To learn a low-carbon lifestyle - each citizen's responsibility (D) To learn a low-carbon lifestyle - a promising but difficult purpose
[A]: D

[Q]: Article: About twenty years ago I had the pleasure of teaching a disabled young woman. Not only was she good at math and science, but she was also extremely talented in art. She could draw and paint beautifully. When Audrey graduated from university she got two degrees, one in fine arts and one in chemistry. Not too many people do well in two such different areas of study. Just before her high school graduation, Audrey gave me a wonderful gift. It was a watercolor1 painting of a mother and her baby. A tear fell from the mother's eye as she looked lovingly at her child. Beneath the painting Audrey had written these words: "The deep love from Mother, through me, touches another." What a beautiful gift! I had the piece of art framed(...) and hung in my office. Years passed with many moves from one office to another and I lost the painting. Last year, after about eight years of not knowing where it was, I received a phone from a former colleague who said she had something of mine. It was the picture Audrey had painted for me 18 years ealier. When cleaning out a storage room she had discovered my gift. I was struck that the precious gift came back. I knew Audrey very well. When she was four years old Audrey had a serious disease. What's worse, her father left the house. It was her mother who brought her up with much trouble. She survived the disease but was disabled. To any other it is just a painting, but to me it shows how a mother's love has helped develop a talent and how its power pushes me ahead.
Question: What made Audrey different from others was that she _ .
Options: (A) could draw and paint beautifullly (B) was good at math and chemistry (C) got two degrees in two different fields (D) was a student in a key university
[A]:
C