In this task, you're given an article and an answer. Your task is to generate the question for the answer based on the given article.
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Question: Article: When a caterpillar feeds on a tomato leaf , the plant moves rapidly to meet with a defensive response , systematically releasing " proteinase inhibitors " -- proteins that interfere with the caterpillar's digestion -- throughout the plant , especially in the leaves . But how does the message get from the wounded leaf to the rest of the plant ? Most scientists believed the alarm was spread by chemical messengers until a team of researchers headed by David Weldon-- a biologist at the University of East Anglia in Norwich , England -- made a shocking discovery . An injured leaf , the researchers found , sends an electrical signal to warn neighboring leaves of upcoming danger . It's a " terribly tiny current " driven by an electrical potential difference of only 20 millvolts , says Weldon , who measured the voltage after electrodes were attached to the plant's surface . " Right now , all we can say is that there is a correlation , " Weldon notes . " If you wound the plant , you'll see an electrical signal accompanied by a biochemical response . " To learn more about the reaction , Weldon's team plans to insert electrodes within the pant tissue ( rather than on the surface ) to determine what's going on at the cellular level . The findings may help explain other mysteries surrounding plants . For example , many plants start to flower in springtime , as days grow longer , but plants sense the change in the day length through their leaves , while flowers begin to bloom at the buds . " There must be a signal from the leaf to the growing points , " Weldon says . " So far , no one has come up with a convincing chemical mechanism . Maybe an electrical signal is involved . "
Answer: They cure diseases by changing chemicals

Answer: What is the function of the " proteinase inhibitors " in tomato plants ?

Question: Article: Using too much water or throwing rubbish into our rivers are clear ways that humans can put our water supply in danger , but we also affect our water supply in less obvious ways. You may wonder how paving a road can lead to less useable fresh water. A major part of the water we use every day is groundwater. Groundwater does not come from lakes or rivers. It comes from underground. The more roads and parking lots we pave the less water can flow into the ground to become groundwater. Human activity is not responsible for all water shortages . Drier climates are of course more likely to have droughts than areas with more rainfall, but in any case, good management can help to make sure there is enough water to meet our basic needs. Thinking about the way we use water every day can make a big difference, too In the United States , a family of four can use 1. 5 tons of water a day! This shows how much we depend on water to live, but there's a lot we can do to lower the number. You can take steps to save water in your home. To start with use the same glass for your drinking water all day. Wash it only once a day. Run your dishwasher only when it is full . Help your parents fix any leaks in your home. You can even help to keep our water supply clean by recycling batteries instead of throwing them away.
Answer: Throwing rubbish into lakes.

Answer: Which of the following is most likely to lead to less groundwater?

Question: Article: "Privacy" is translated as "yin si" in Chinese. Traditionally,in the Chinese mind,"yin si" is associated with(...)what is closed or unfair. If someone is said to have "yin si",meddlers will be attracted to pry into his or her things. So people always say that they don't have "yin si". On the contrary, Americans often declare intention to protect their privacy. Their understanding of privacy is that others have no right to pry into things which belong to themselves alone and have nothing to do with others. One who is too curious and who spreads rumors is said to violate the right to privacy. In the evening, Sonia and I went to a bar for dinner. In China, when people mention bars, something bad usually comes to mind. But here,the bar was a quiet and tastefully laidout place. People spoke quite softly, afraid of interrupting their neighbors, and sat face to face as they drank, sometimes three or five persons sitting together. This sort of atmosphere was totally different from my preconception , so I wanted to take a picture. Sonia stopped me, "Don't you see these people are pouring out their hearts? Maybe they are colleagues, friends, secret lovers. They came here looking for a peaceful place free from interruption by others. They wouldn't want to leave any trace of their having come here. So taking their pictures would be a serious violation of their right to privacy." Is there privacy between husband and wife? One of Sonia's friends married a talented Chinese man,but recently she became so angry that she wanted a divorce .The reason was that her husband had opened one of her letters and looked through her purse. The husband didn't realize that this is not tolerated in the U.S.. He thought that being a couple was like being one person; why couldn't he see the letter or the contents of the purse? Truly, everyone, even those living as a couple, needs room--not only in threedimensional space, but in the heart.
Answer: The understanding of "privacy" is different in China and America.

Answer:
What is the main idea of the text?