4．He was sitting in the office，and he was lost in thought.

　　He was sitting in the office，lost__in__thought．

　　5．Unless she is invited，she won't attend his wedding.

　　Unless__invited，she won't attend his wedding.

　　6．Although he is introduced to the young man，he still stands there silently.

　　Although__introduced to the young man，he still stands there silently.

　　短语动词

　　短语动词由动词与名词、介词、副词等结合在一起组成，主要有如下几类。

动词＋名词 这种词组由及物动词加名词构成。要注意名词前是否有冠词，名词是否可数。 drop a line写封简信

take medicine服药

make way前进

catch the train赶火车

have a try试一下 动词＋介词 这种词组后面都能带名词或相当于名词的成分作宾语，但不一定都能变成被动语态。要特别注意介词的固定搭配。 live on以......为食

succeed in成功

result from由......造成

depend on依靠，取决于

result in导致

agree with同意 动词＋副词 这种词组有些能带宾语。如果宾语是代词，须放在动词后面、副词前面。如：put it on不可以说put on it。要注意其中副词的固定搭配。 make up弥补；化妆

give out分发；散发

make out弄明白

figure out弄懂；算出