根据汉语及英语提示，填入适当的词，使句子完整、通顺。

1. 谁该对这次交通事故负责?

Who is to _________ __________ the car accident?

2. 他的车在上班的路上坏了.

Yesterday his car __________ ___________ on the way to work.

3. 塑料已经替代了许多其它材料.

  Plastics has __________ ________ ________ _______ many other materials.

4. 除了集邮外他还喜欢干什么？

What does he like to do _________ __________collecting stamps?