Read the article and select the best answer. Article: Why did humans evolve to walk upright? Perhaps because it's just plain easier. Make that "energetically less costly", scientifically speaking. Bipedalism--walking on two feet, is one of the defining characteristics of being humans, and scientists have debated for years how it came about. In the latest attempt to find an explanation, researchers trained five chimps to walk on a treadmill while wearing masks that allowed measurement of their oxygen consumption. The chimps were measured both while walking upright and while moving on their legs and knuckles .That measurement of the energy needed to move around was compared with similar tests on humans and the results are published in this week's online edition of "Proceedings of the National Academy of Sciences". It turns out that humans walking on two legs use only one-quarter of the energy that chimps use while knucklewalking on four limbs .And the chimps, on average, use as much energy using two legs as they did when they used all four limbs. However, there were differences among chimps in how much energy they used, and this difference corresponded to their different manner of walking and anatomy .One of the chimps used less energy on two legs, one used about the same and the others used more, said David Raichlen, assistant professor of anthropology at the University of Arizona. "What we were surprised at was the variation ", he said in a telephone interview. Interview. "That was pretty exciting, because when you talk about how evolution works, variation is the bottom line, without variation there is no evolution." Walking on two legs freed our arms, opening the door to drive the world, said Raichlen. "We think about the evolution of _ as one of first events that led hominids down the path to being humans." The research was supported by the National Science Foundation and the L.S.B.Leakey Foundation. Question: We can infer from the passage that _ . Options: A: scientists have no idea on how humans' walking on two legs came about B: scientists have had different views on why chimps walk on four legs C: scientists have had different views on how humans' walking on two legs vame about D: scientists have had similar views on how humans' walking on two legs came about
C

Read the article and select the best answer. Article: One day I was driving to a business appointment and, as usual, I was planning in my mind what I was going to say. I came to a very busy crossroad where the stoplight had just turned red. A young couple, both blind, were walking across the road. Each of them had a white cane . They were overcoming the most feared blindness. I held my breath when I noticed that the couple was not walking on the crosswalk, but was instead stepping directly into the middle of the crossroad. Without realizing the danger they were in, they were walking right into the path of the oncoming cars. I was frightened for them because I didn't know if the other drivers understood what was happening. Then I saw a _ unfold before my eyes. Every car in every direction came to a stop at the same time. Nobody can yelled, "Get out of the way!" Amazed, I noticed that everyone's attention was also fixed on the couple. Suddenly the driver to my right reacted. He yelled, "To your right."Other people followed, shouting, "To your right!"Trusting their elite canes and the calls from some concerned citizens, they made it to the other side of the road. I could judge they had no idea what was really going on around them. Yet I immediately felt smiles appeared on everyone's face. The driver to the left of me was saying, "I can't believe it!" I thought all of us were deeply moved by what we had just seen. Here were human beings stepping outsides themselves for a while to help other people in deed. Question: When the author drove to work, he saw _ . Options: A: some drivers were driving their cars very fast B: a couple failed to cross the road as usual C: most drivers drove in the same direction D: A blind couple was walking into the driveway
D

Q: Read the article and select the best answer. Article: Sometimes life gets a little dull. What used to be fun and different becomes boring. That is the time to look for something new. It is the time for a big idea to get your mind off everyday life. So why not search for extraterrestrial intelligence? Or even better, why not get your computer to do it for you? Over two million people have joined the Search for Extraterrestrial Intelligence(SETI)project. Based in California, the SETI project analyzes information taken from a giant radio telescope based in South America. Its task is to look for signals from outer space that might prove that life exists on other planets. Processing this information is far too big a job for one computer. So the SETI project workers divide the work among volunteers who visit their website. Each computer gets some information to work out from the SETI network through the Internet. This process is often known as "meta-computing". It is a wonderful thought. You are sleeping, eating a meal or going out with friends. All this time, your computer is searching the stars for signs that might show something is out there trying to get in touch. Volunteers are proud of being involved in the SETI project. It shows that they understand the potential of computing. They know that it is more than just a way of working or playing games. Meta-computing may also be creating intelligence as well as looking for _ . This idea is based on the theory that human intelligence is created by the way in which different parts of the brain communicate with each other. As the saying goes, "The whole is more than the sum of its parts." People who join the SETI project sometimes wonder whether their computer will become part of a huge network that has learned to think for itself. Question: According to the writer, meta-computing may be creating intelligence _ . Options: A: because human beings are intelligent B: because a computer works as the brain does C: because of a network of many computers D: because of the number of computers
A: C

Read the article and select the best answer. Article: Hamsters are lovely small animals which are similar to mice, and some people like to keep them as pets. They need to eat a balanced diet, or they can become very sick. That's why hamsters should be fed healthy foods. Most pet stores sell hamster mix. This is a combination of foods that are just right for hamsters. Some hamsters are picky eaters. They don't eat anything they don't like, so you have to find a hamster mix that your hamster will like. Most hamsters only eat a few tablespoons a day. You should feed them at the same time every day, or you can just keep your hamster's bowl full. Remember to clean the bowl at least once a week. Hamsters also drink a lot of water, so be sure to keep the water supply full and fresh. Just like people, hamsters like treats. Besides the hamster mix, you can sometimes feed your hamster seeds, nuts, and some other people food. You should never feed your hamster anything unless you are sure that it is safe for hamsters. Feed your hamster carefully, and always take good care of your pet! Question: What's the passage mainly about? Options: A: Where to keep hamsters. B: When to buy hamsters. C: What to feed hamsters. D: Why to raise hamsters.
C