用所给单词的适当形式填空。

1. What can you see in ______ (this) pictures?

2. ______ (run) is good for our health.

3. There ______ (be) lots of things in our school.

4. He doesn't like ______ (tomato).

5. Do you have a set of ______ (key)?

可用于火箭发射的多种助推剂中，液氢、液氧是最环保的，我国计划 2015年首飞的长征5号运载火箭，它的一级、二级都采用液氢、液氧作助推剂．若为火箭加注100吨液氢燃料，应加注多少吨的液氧助推火箭发射？