雕像《伏尔泰》头上的束发带，象征（）。

用“who”或“that”填空。  

1. The man ________ is talking with my mother is my father

2. That book is the one _______ I bought yesterday .  

3. He is one of the workers ________ been saved in that accident .  

4. They talked of the things and persons ________ they remembered in the

factory .  

5. All ______ can be done must be done .