_______ (devote) himself to finding out information, the researcher forgot to sleep.

________ (devote) to finding out information, the researcher forgot to sleep.

________ (occupy）in a very important experiment he would not attend the party.

请教专家，按照道理，1，2，3题主语和他们的关系都是主动的，都应该用 Devoting和Occupying但是结果不都是。个人感觉无法通过主语和从句的动词方面去解释？那请教专家，具体应该怎么去解释才好理解？谢谢！