用所给单词的适当形式填空。

1. _____ (be) your mother in Beijing last week?

2.  He often  _____ (play) basketball after school when he was a studerit.

3.  —What  ______you_____ (do) last night?

    —I _____ (watch) TV with my parents.

4.  —Why_____Iucy_____ (sleep) in the class this morning?

    —Because she went to bed very late last night.

5.  I _____ (forget) to bring my MP3 with me today.

在元素周期表中金属和非金属元素的分界线的附近可以找到（　　）

A．研制新型农药的元素

B．制造半导体材料的元素

C．制造催化剂的材料

D．制造耐高温的合金材料