用所给单词的适当形式填空。

1.My mother always ________ (cook) meat for me.

2.He is ________ (read) a book in the living room now.

3.Let's________ (make) a big cake.

4.I always________ (wash) dishes for my mother.

5.He wants to be a ________ (drive) in the future.

化学致畸作用的基本特征（）

A.致畸作用具有生物敏感期

B.其剂量-反应关系属于有阈值关系

C.致畸性存在种属差异

D.致畸物可通过胎盘转运和转化

E.A+B+C+D