1、A shop should keep a stock of those goods which sell best.

商店应存有最畅销的货物。

2、This is the family which is planning to move to the city

这是要搬进城里的一家。

3、This is a reason which we must not forget.

这是我们不能忘记的一个原因。

4、When deep in thought, which he often was, he would forget all around him.

他常常陷入沉思，这时他就会忘掉周围的一切。

5、He bought a book, which was written by LuXun, and which he decided to give to his friend.

他买了本鲁迅写的书，他决定送给朋友。