He has devoted his whole life to benefiting mankind.

The girl, to whom he was devoted, died in a traffic accident by chance.

After he has retired, he will devote himself to gardening.

4. behave

【课文原句】Jane has studied these animals for many years and helped people understand how much they behave like humans. (P2)

【名师点拨】behave vi & vt. 意为"举动；举止；行为表现"，如behave well / badly等。其名词形式为behaviour，指"行为；态度；举止"。如：

The parents encouraged the children to behave well in front of the guests.

My camera has been behaving well since it was repaired.

Everyone praises the children's good behaviour.

5. worthwhile

【课文原句】But the evening makes it all worthwhile. (P2)

【名师点拨】worthwhile adj.意为"值得做的；值得出力的"，可作表语或定语。be worthwhile to do / doing sth表示"值得做......"，在动词-ing形式的结构中，worthwhile有时可以用来替代worth，特别是在表示"值得花时间"这一概念时。如：

I think teaching school is always a worthwhile job.

The book referred to by the professor is worthwhile / worth reading.

6. observe

【课文原句】Jane spent many years observing and recording their daily activities. (P2)

【名师点拨】observe vt. 意为"观察；观测；遵守"，可用observe sb do sth，observe + that从句。其名词形式为observation。如：

I observed the man who murdered the boy enter the shop.

He observed that we should probably have rain.

Most information was collected by direct observation of the animals' behaviour.

7. argue

【课文原句】She has argued for them to be left in the wild and not used for entertainment or advertisements. (P2)