为控制人口数量和提高人口素质，我国已把计划生育列为一项基本国策，其具体要求是晚婚、晚育，____和____。

热机是把____ 能转为____ 能的机器．燃料直接在发动机气缸内燃烧产生动力的热机叫做内燃机，常见的内燃机有____ 和____ 两种．

根据短文内容，完成下列各题。

    Fire can start in forests, homes and schools. It is very dangerous. What should we do when there is a fire? We should go outside quickly. And we have a fire drill at school every year.

    A fire drill is not a real fire, It helps us prepare for(为……准备) a real fire. This map tells us the way in a fire. We can follow the fire exit(出口) signs too. First, the fire alarm sounds. Next, we all line up and go out quickly. We leave all our things in the classroom. Then we walk down the stairs and go outside. We line up in the playground. Our teacher checks on the number of students. We should wait for the firemen to come.