改变括号中单词的首字母，使之变成新词填入句中，使句意完整。

1. I have ______ (your) eggs.

2. Good ______ (eight), Daddy.

3. ______ (That) is  that , Judy?

4. Show me your ______ (boot).

5. The ______ (pear) is sitting on the chair.

什么叫过滤周期？受什么因素影响？如何确定？