关于地球同步卫星，下列说法正确的是（　 　）.

①地球同步卫星和地球同步，因此同步卫星的高度和线速度大小是一定的

②地球同步卫星的角速度虽被确定，但高度和线速度可以选择，高度增加，线速度增大，高度降低，线速度减小

③地球同步卫星只能定点在赤道上空，相对地面静止不动

④周期是24小时的卫星一定是同步卫星

A．①③

B．②③

C．①④

D．②④

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。

Getting up early has been regarded as a good habit since ancient times．Many years ago, people thought that if we went to bed early and got up early, we would be energetic the whole day．So, getting up early is of great importance to us all．

In fact, morning is the best time of a day．In the morning, the air is the freshest and people are usually in the best conditions．Many of us may have the experiences that we memorize some things more quickly and accurately in the morning than at any other time of the day．If we do some morning exercise or only take a short walk in the morning, we can build our bodies and become much healthier．Also we will have enough time to make a plan and get ready for our work or study of the day if we get up early．However, if we get up late, we'll probably have to do everything in a great hurry．

Let us remember getting up early is a good habit and try our best to keep it．If we stick to getting up early every day, we will certainly benefit a lot from it．

【写作内容】

1．以约30个词概括短文的要点：

2．然后以约120个词就“早起还是晚起好”这个主题发表你的看法，并包括以下要点：

（1）你喜欢早起还是晚起? 为什么？

（2）你的父母或教师有何看法？

（3）你如何看待他们的看法？

【写作要求】

可以使用实例或其它论述方法支持你的论点，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：

【评分标准】概括准确、语言规范、内容合适、篇章连贯。