是Enthusiasm。

例句有

1、He brought to the job not just considerable experience but passionate enthusiasm

他不仅给这一工作带来了不少经验，而且倾注了极大的热情。

2、The masses have a vast reservoir of enthusiasm.

群众中蕴藏了极大的积极性。

3、He commended them for their enthusiasm.

他称赞他们的热情。