We all enjoy the beautiful show of color1s as leaves change each autumn. But did you ever wonder how and why this happens? To answer the question, first you have to understand what leaves are and what they do. Leaves are nature's food factories. Plants take water from the ground through their roots. And they take a gas called carbon dioxide from the air. Plants use sunlight to turn water and carbon dioxide into glucose . Glucose is a kind of sugar. Plants use glucose as food for energy and as a building block for growing. The way plants turn water and carbon dioxide into sugar is called photosynthesis . That means, "putting together with light". A chemical called chlorophyll helps photosynthesis. Chlorophyll is what gives plants their green color1. As summer ends and autumn comes, the days get shorter and shorter. This is how trees "know" to begin getting ready for winter. During winter, there is not enough light or water for photosynthesis. Trees rest during this time and live off the food they stored during the summer. They begin to shut down their food-making factories. The green chlorophyll disappears from the leaves. As the bright green fades away, we begin to see yellow and orange leaves. Small amounts of these color1s have been in the leaves all along. We just can't see them in the summer, because they are covered up by the green chlorophyll. The bright reds and yellows we see in leaves are made mostly in autumn. In some trees, like maples, glucose is caught in the leaves after photosynthesis stops. Sunlight and the cool nights of autumn turn this glucose into a red color1. The brown color1 of trees like oaks is made from waste left in the leaves. It is the mixture of all these things that makes the beautiful color1s we enjoy during autumn. Which of the following about chlorophyll is NOT true? A) Without it photosynthesis couldn't happen. B) It is the reason why leaves have their green color1. C) It turns the leaves red during autumn. D) It is a chemical that's important for trees' food making.
C
(Question)
Although cats may be one of the most popular pets today, little is known about how and when humans and cats set up their close relationship. The earliest evidence for human-cat interaction dates back to prehistoric Cyprus , where the remains of a wild cat and a human -- dated 9,500 years old -- were found buried together. A new study in the Proceedings of the National Academy of Sciences has confirmed the first direct evidence of a human-domestic cat relationship among Chinese farmers 5,300 years ago. Researchers studied the bones of cats, dogs, deer and other animals unearthed in an excavation near a village in Central China. By using some ways, scientists showed that the cats were living on a mostly millet -based diet, just like the domesticated dogs and pigs from the site. "The most reasonable explanation for a high consumption of millet-based food is that the cats had formed a stable and mutual relationship with humans and could easily feed on rodents around human villages, find leftover food or even have been fed by people intentionally," said Hu Yaowu from the Chinese Academy of Sciences in Beijing, whose research focuses on the relationship between humans and domesticated animals. "It is very interesting for us to find the consumption of millet-based foods by the cats, since this kind of evidence had long been missing." Hu explains. Since cats usually eat meat, such a diet would be unexpected, unless the cats were being fed by people, the study argues. The researchers also found that one of the cats survived to reach old age, implying that it had a safe place to live and enough to eat. Why the farmers wanted to keep cats nearby or make them "pets" could be answered by other evidence. Chinese archaeologists found some storage containers were specifically designed to keep out rodents -- a vermin that cats could certainly have helped with. The simplified theory is that rats were attracted to the food of farmers, and so were harmful to farmers. Cats were attracted to the rats, and so farmers formed a... The evidence found in the remains dating back to prehistoric Cyprus means _ . A) human made cats pets as early as 9,500 years ago B) human interacted with cats very early C) cats didn't appear until prehistoric Cyprus D) when cats became domesticated
(Answer)
B
Ques: I used to watch her from my kitchen window. She seemed so small as she muscled her way through the crowd of boys on the playground. The school was across the street from our home and I would often watch the kids as they played during break. I remember the first day I saw her playing basketball. I watched in wonder as she ran circles around the other kids. She managed to shoot jump shots just over their heads and into the net. The boys always tried to stop her but no one could. I began to notice her at other times, basketball in hand, playing alone. One day I asked her why she practiced so much. Without a moment of hesitation she said, "I want to go to college. The only way I can go is to get a scholarship. I am going to play college basketball. I want to be the best. My Daddy told me if the dream is big enough, the facts don't count." Well, I had to give it to her--she was determined. I watched her through those junior high years and into high school. Every week, she led her school team to victory. One day in her senior year, I saw her sitting in the grass, head in her arms. I walked across the street and sat down in the cool grass beside her. Quietly I asked what was wrong. "Oh, nothing," came a soft reply, "I am just too short." The coach told her that at 5'5" she would probably never get to play for a top ranked team--much less offered a scholarship--so she should stop dreaming about college. She was heartbroken and I felt my own throat tighten as I sensed her disappointment. I asked her if she had talked to her dad about it yet. She told me that her father said those coaches were wrong. They just did not understand the power of a dream. He told her that if she truly wanted a scholarship and that nothing could stop her except one thing -- her own attitude. The next year, as she and her team went to the Northern California Championship game, she was offered a scholarship and on the college team. She was going to get the college education that she had dreamed of. Why was the girl heartbroken? A) She was considered too short to be a top player. B) Her coach stopped her training because of her height. C) She couldn't be on a college basketball team. D) She wouldn't be admitted by an ideal college.
Ans: A
Ques: Why did the chicken cross the road? To get to the other side. Most people know this joke. But recently, some people have been much more worried about how the grizzly bear and mountain lion can cross the road. "Millions of animals die each year on U.S. roads," the Federal Highway Administration reports. In fact, only about 80 ocelots, an endangered wild cat, exist in the U.S. today. The main reason? Roadkill. "Eco-passages" may help animals cross the road without being hit by cars. They are paths both over and under roads. "These eco-passages can be extremely useful, so that wildlife can avoid road accidents," said Jodi Hilty of the Wildlife Protection Society. But do animals actually use the eco-passages? The answer is yes. Paul Beier of Northern Arizona University found foot marks left by mountain lions on an eco-passage that went under a highway. This showed that the lions used the passage. Builders of eco-passages try to make them look like a natural part of an area by planting trees on and around them. Animals seem to be catching on. Animals as different as salamanders and grizzly bears are using the bridges and underpasses. The next time you visit a park or drive through an area with a lot of wildlife, look around. You might see an animal overpass! The best title for the passage is _ . A) Special bridges help animals cross the road B) Endangered animals increase because of roadkill C) Animals fail to cross the road D) Take steps to protect animals in danger
Ans:
A