下列各句中，没有语病的一句是（    ）

    In our daily life, some people think that smoking1help them relax. In fact, smoking is really2 Do you know that there are over 4,000 chemicals（化学药品） in cigarettes? These chemicals are 3for our bodies. They can cause cancer and 4diseases.

    The smoke from cigarettes harms not only smokers but also other people. It's5“second-hand smoke” and it can be6and has higher risks. Smokers shouldn't use smoking7them relax. They must give up smoking as soon as possible.

作文：
       社会是一个大家庭，我们每个人都是其中一分子。随着时代的发展，人与人之间的联系越来越紧密，团结、友爱、互助成了现代人必不可少的社会素养。只有拥有这些优秀的品质，社会才能融洽和睦、协调发展。

       请以“我想握住你的手”为题．写一篇不少于600字文章。

       要求：①联系自己的生活体验写作；②除诗歌、戏剧外，文体不限；③文中不要出现真实的人名、地名、较名等。

如果$a,b,c$满足$c<b<a$且$ac<0$，那么下列选项中不一定成立的是（   ）