which引导的定语从句在英语语法中，尤其是在定语从句中是比较常见的，经常在做题或者阅读过程中会遇到，也许你对它的用法不大熟练,不妨从现在开始背背下面的句子:

A shop should keep a stock of those goods which sell best.
商店应存有最畅销的货物。

This is the family which is planning to move to the city
这是要搬进城里的一家。

This is a reason which we must not forget.
这是我们不能忘记的一个原因。

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。

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。

There is a special parasite which gives rise to the itch.
有一种特别的寄生虫会导致皮炎。

He told a story which moved us deeply.
他讲了一个使我们深受感动的故事。

In the presence of so many people he was little tense, which was understandable.
在那么多人面前他有点紧张，这是可以理解的。

He may have acute appendicitis，in which case he will have to be operated on.
他可能得了急性盲肠炎，如果是这样，他就得动手术。

When deeply absorbed in work，which he often was，he would forget all about eating and sleeping.
他经常聚精会神地工作，这时他会废寝忘食。

好了，以上的这些例句请大家一定要熟读。定语从句是语法中的难点，希望大家通过练习来逐渐透彻掌握。最后，预祝大家每天都学到新知识。