题干

小明从今年1月初起刻苦练习跳远,每个月的跳远成绩都比上一个月有所增加,而且增加的距离相同.2月份,5月份他的跳远成绩分别为4.1m,4.7m.请你算出小明1月份的跳远成绩以及每个月增加的距离.

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答案(点此获取答案解析)

解:设小明1月份的跳远成绩为xm,则

4.7﹣4.1=3(4.1﹣x),

解得x=3.9.

则每个月的增加距离是4.1﹣3.9=0.2(m).

答:小明1月份的跳远成绩是3.9m,每个月增加的距离是0.2m.

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阅读理解

    Elephants in Uganda are starting to come close to villages near national parks. The big animals are a real danger to people.

    So, the Uganda Wildlife Authority has been giving people new tools to keep the elephants away: vuvuzelas. They are plastic instruments some fans use at sports events.

    The instruments make a loud sound elephants do not like. The animals leave, and no one is harmed. A spokesperson for the Uganda Wildlife Authority says vuvuzelas work because they do not threaten the elephants. That is important because an elephant that feels threatened is more likely to attack. So far, no one has reported an elephant attacking in answer to a vuvuzela.

    Officials and villagers have tried other ways to stop elephants from coming near farms and houses. They have built beehives – houses for flying insects that sting. They have hung ropes covered in spicy oil. They have dug long, deep holes. And they have used guns, called A-K47s.

    An official from the Uganda Wildlife Authority explains that people shoot the gun in the air to scare the elephant. But over time, the elephants have stopped being afraid of the sound of the gun. They only look at the shooter and wave their ears.

    Another official for the Uganda Wildlife Authority, Gessa Simblicious, says one elephant-prevention solution will not work everywhere in Uganda. And one day, elephants may accept the vuvuzela noise, just as they do the sound of the A-K47.

    But right now, vuvuzelas are an effective, non-violent and fun way to deal with a serious problem.