题目

下图表示野兔种群数量变化的四种情况（I、Ⅱ、Ⅲ、Ⅳ），其中在a、b点时发生相关变化。请据图回答问题： （1） Ⅳ为20世纪初期澳洲野兔的种群数量变化曲线，该种类型的种群增长称为形增长。自然界中，绝大多数野兔种群不可能以Ⅳ的形式增长，其原因有（答出两点）。 （2） 某地区a点时人类大量捕杀了某大型肉食动物（野兔天敌），由此导致野兔的种群数量发生变化，其变化趋势最可能是图中的曲线。 （3） 调查野兔种群                            我们为什么近视？   As the information technology is more and more developed,computers and high technology products have entered so many families. So our eyesight is lower and lower day by day when we do something with computers. From now on,it is time for us to protect our eyes. Don’t let the shortsightedness become the trouble for us.   Around me,lots of teenagers have worn glasses; it is such a terrible problem for us. What makes our eyes worse?   Firstly,computers are friends for many people,and also there are many people who buy notebooks or personal computers for themselves;someone uses them for working,studying,playing games and so on!   Secondly,for the working groups,it is so easy to become shortsighted for these people who are facing the computer for long time every day. Other people who work outside usually chat online with their friends,write diaries and study in their spare time,etc.   Thirdly,for teenagers,it is easy to become shortsighted,because they like playing games or sending messages and using QQ by mobile phones.   We should try our best to go to bed earlier,come out and breathe the fresh air,look at the green trees. It will be good for our eyes.() 1. The writers gives reasons that can cause shortsightedness.   A. one   B. two   C. three   D. four() 2. Which is not true according to the passage?   A. All the people are shortsighted.   B. If you take good care of your eyes,you won’t suffer from shortsightedness.   C. If you use the computer too much,you may be shortsighted.   D. Looking at the green trees is good for our eyes.() 3. suggestions on being good for our eyes are mentioned.   A. Five   B. Four   C. Three   D. Two() 4. People can use mobile phones to .   A. play games   B. send messages   C. chat online   D. All above