Every day in China, about 200 million children go to school. Many of them take school buses to school and back home. Most of the time, the school buses are very safe for them. But sometimes they are also dangerous.

    Several years ago, a serious accident happened to a nine – seat minibus in November in Gansu. There were 62 children inside, and 21 of them died.

    What should we do to keep us safe on the road? First, we should wait for the school bus on time at the right place when we are going to school or coming back home. Second, we shouldn't run or fight on the bus when it is going. Third, we mustn't try to get off when it is moving. Last, don't get on the bus if it is overloaded(超载).

    Our government(政府)also makes rules for school buses. Under the new rules, school buses have a speed limit of 80km per(每)hour on highways and 60km per hour on normal roads. While on the road, other cars must let school buses go first.

根据材料内容选择最佳答案。

There are many kinds of animals ____ ____ in nature.

辨析题： 
党的十八大报告强调，确保到2020年实现全面建成小康社会的目标。有人认为：全面小康实现后，我国百姓的生活将更加幸福，艰苦奋斗的精神将过时。

Dear Abby，

    I'm a helpless mother. My son Tom is 15 years old. I find that the older he grows， the less we talk. I feel very sad and I really need help.

    My first problem is about his hobbies. He spends almost all his spare time on computer games. When he gets home， he always turns on the computer and closes the door. I'm getting worried about him， especially when his English teacher tells me he always gets low marks in the English exams.

    Second， he likes new technology， but I don't have enough money and I can't afford all the things he wants.

    Recently， I've found that he is always alone. I've never seen him talking to his friends on the phone or going out with anyone on weekends. That is the last problem I have.

    What should I do to help him? Please give me some advice.

A helpless mother

一个小球静止在水平桌面上，试画出小球对水平桌面的压力F的示意图．