阅读下面的短文，请根据短文后的要求答题（请注意问题后的字数要求）［1］In a study likely to make school caretakers embarrassed

阅读下面的短文，请根据短文后的要求答题（请注意问题后的字数要求）
［1］In a study likely to make school caretakers embarrassed, U.S. researchers said that chewing gum may help improve performances of teenagers. Many schools ban chewing gum because children often throw away the sticky chaw under chairs or tables. But the study found that students who chewed gum during math class had higher scores on a math test and better grades than students who did not chew gum in the class.
［2］“For the first time, we’ve been able to show in a real-life kind of situation that students did perform better when they were allowed to chew,”said Gil Leveille, director of the Wrigley Science Institute. Wrigley has gotten feedback from many of its gum customers who say chewing gum helps them stay focused.
［3］The researchers studied four math classes（108 students aged 13 to 16）.About one half got free Wrigley’s sugar-free gum to chew during class, homework and tests. They chewed at least one stick of gum 86 percent of the time they were in math class and 36 percent of the time they were doing homework. The other half    .
［4］After 14 weeks, the gum chewers had a 3 percent increase in their math scores on the Texas Assessment of Knowledge and Skills achievement test, a small but significant change. As a matter of fact, the gum chewers did get better final grades in the class than their non-chewing peers.
［5］Leveille said chewing gum helps reduce stress, so students can do their best work. And while he is aware that many schools have a dim view on students’ chewing gum in class, he hopes the findings may change that a bit.
［6］“It’s not a matter of chewing. It’s a matter of gum disposal（处理），”Leveille said, adding that it can be overe by teaching proper disposal methods. If that failed, he joked, “We’ll have to provide the cleaners with scrapers（刮刀）”
【小题1】What is the main idea of the passage？（no more than 10 words）
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【小题2】In what way is chewing gum helpful according to the passage?（no more than 10 words）
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【小题3】Fill in the blank in Paragraph 3 with proper words.（no more than 8 words）
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【小题4】Which sentence in the passage is the closest in meaning to the following one?
Although he knows many schools are against students’ chewing gum, he expects that the research results will help improve the situation.
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【小题5】According to Leveille, why should schools deal with the problem in gum chewing?（no more than 10 words）
      _        Chewing gum can raise grades of teenagers. /Chewing gum may help improve performances of teenagers.