题目

阅读下面的文字，完成6―9题。从前，稍微精确一点说，两亿年前，世界上还没有花。后来，有了蕨类和苔藓，有了松类和苏铁类。但是，这些植物并不形成真正的花和果，其中一些是无性繁殖，以种种手段来克隆自己。有性繁殖是经过相对发展的事情，通常与花粉被释放到风中或水里有关。由于一些纯粹偶然的机会，花粉到了到达这一种类其他成员那里的途径，一颗小小的、原始的种子就产生了。与现在相比，这个有花之前的世界是一个更为缓慢、短文改错（共10小题；每小题1分，满分10分）From the picture, we can see that there are many students are wearing glasses, that is, they are short-sighted. As we all know, which is important for everyone to keep good eyesight. But do you know how to protect your eyesight? First, don’t keep your eyes work for a long time. You’d better have rest after you have studied an hour or so. Second, pay much attention to the following. Don’t read under the sun or in a poorly light; don’t read in bed or in a moved bus. Third, do eye exercise every day. It will also help you keep good eyesight. But last you should have enough sleep. Only you obey the rules above can you prevent your eyesight from becomingshort-sighted.