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问题 问答题 简答题

轴流状态下，桨叶各切面的周向气流速度u的大小如何表示？直升机前飞时，桨叶微段的周向气流速度如何表示？

答案

参考答案：

轴流状态下，桨叶各切面的周向气流速度u的大小是u=Ωr；直升机前飞时，桨叶微段的周向气流速度为u=Ωr＋Vcosαssinψ。

写作题

第二节 读写任务（共 1小题；满分 25分）

阅读下面的短文，然后按照要求写一篇 150词左右的英语短文。

Teenagers’ secrets should be kept to themselves and no one else, their parents included, has the right to stick their nose into their private life.

As we know, teenagers are going through a special period of development both physically and psychologically. They are curious about and puzzled by the unexpected changes in their body and mind. What’s more, exposed to a world of adults, it is only too natural for them to begin imitating adults’ behaviors in secret. Boys begin to smoke and girls begin to spend time doing their hair and care more about what to wear. Some even begin to date with a girlfriend or boyfriend without letting their parents know. They are doing all this in secret because they are still unsure whether it is right to do so and afraid that, if found out by their parent, they will get misunderstood and even punished. In fact, in many cases, parents can not deal with such matters well but hurt their children’s feelings badly, making children unwilling to communicate with them any more. When this happens, it hurts terribly feelings of the family as well. Therefore, it sounds reasonable and acceptable that teenagers should keep their secrets to themselves instead of sharing them with their parents, who should give them the freedom in dealing with secrets.

【写作内容】

1. 以约30个词概括上面文章的要点；

2. 然后以约120个词就“青少年的秘密该不该与父母分享”这一话题发表你的看法，至少包含以下内容：

1）你是支持还是反对与父母分享秘密？

2）你支持或反对的理由是什么？

3）结合你的实际, 谈谈你是具体怎么做的？

【写作要求】

1. 在作文中可以使用自己亲身的经历或虚构的故事，也可以参照阅读材料的内容, 但不得直接引用原文中的句子；

2. 作文中不能出现真实姓名和学校名称。

3. 题目自拟。

【评分标准】概括准确，语言规范，内容合适，篇章连贯。
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单项选择题

推广商品的标题不能超过多少汉字（）

A.10个汉字

B.20个汉字

C.30个汉字

D.40个汉字
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