根据汉语提示完成句子，每空一词。

1. 你把所有的数加起来就会知道结果。

    ____ up all the numbers ____ you will know the result.

2. 学很多而不使用是没有用的。

    It is ____ ____ learning a lot ____ using.

3. 这是她本周第三次上班迟到了，是不是？

    This is the third time that she ____ ____ late for work this week, isn't it?

4. 妈妈问她穿这么多衣服是不是很热。

    Mother asked her whether she was very hot ____ so many clothes____.

5. 你昨天不应该去看电影；你应该先完成作业。

    You ____ have gone to see the movie yesterday. You should ____ ____ your homework first.

6. 我不知道为什么如此多的学生对流行音乐如此狂热。

    I ____ why so many students are so ____ about popular music.

风管垂直安装，间距不应大于（），且单根直管至少应有2个固定点。

A.4m

B.4.5m

C.5m

D.6m