在一个稳定的化工生产过程中，我们向一个系统或设备中加入的热量，必须（）放出和损失的热量。

A、等于

B、大于

C、小于

D、大于或等于

根据句意及首字母提示填空。

1. Many young people want to j_____ the music club.

2. Does your sister know any other Latin American d_____?

3. S_____ is the first day of the week.

4. He likes writing e_____ to his pen pal abroad.

5. I forgot her a_____, so I didn't attend her birthday party.