用洋葱鳞片叶表皮制备“观察细胞质壁分离实验”的临时装片，观察细胞的变化。下列有关实验操作和结果的叙述，正确的是  （   ）

    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.