Read the following article and select the best answer. Article: 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. Question: From the text we can see that photosynthesis _ . - can produce glucose, which can provide energy for trees' growth - can happen whenever there is light and water - is the process of putting sunlight together with chlorophyll - doesn't stop during the trees' lifetime even in winter
can produce glucose, which can provide energy for trees' growth

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Read the following article and select the best answer. Article: 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... Question: Apart from cats, Hu Yaowu and his teams may also study _ . - the preventions of pests from grains - the history of Chinese farming - the dogs and pigs - the ways to keep pets
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the dogs and pigs

Ques: Read the following article and select the best answer. Article: If you have ever experienced jet lag ,you know how much of a drag it can be. Jet lag happens as a result of air travel, when traveling between two or more time zones. Your body is used to operating in a certain time zone, and when its timing is affected, you're likely to have problems. Edward Norton's character in the movies Fight Club faces the struggle of jet-lag-induced sleeplessness due to his constant traveling. Sleeplessness is just one of the effects of jet lag, and it can lead to other problems, such as tiredness, memory loss and confusion. That's not something you should have to fight on a business trip and it certainly won't make your vacation very enjoyable, either. Sleeplessness is the biggest problem for travelers that suffer from jet lag. Don't worry. You can do something to prevent it. Modify Your Body Clock To prevent the effects on your body's timing that come with crossing time zones, you need to change your body clock sooner, rather than later. You can do this by putting yourself on the same time as your destination time zone before you fly. If you know that you will be traveling to London from the eastern United States, you'll have a five-hour time difference to deal with. Plan for it. Avoid Heavy Food and Alcohol Part of the pleasure of flying commercially, especially if you fly business or first class, is taking advantages of the food and drinks. If you want to avoid jet lag, though, you should think twice. Eating heavy food will only make the jet lag worse. It isn't good to drink alcohol during a flight, either, because it may make you drowsy. Wait until your body adjusts before you decide to have heavy food or drink alcohol. Question: What is the main idea of the passage? - What jet lag is and the effects it has. - What jet lag is and the movies about it. - How jet lag happens and how to fight it. - How jet lag happens and tips on traveling safely.
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How jet lag happens and how to fight it.