教小孩子的好处之一是他们热情高涨。

One of the good things about teaching young children is their ___enthusiasm.

事故后，他对这项运动失去了热情。

After the accident he lost his ___enthusiasm for the sport.

我充满了热情，期待在美国加利福尼亚营度过两周。

I am filled with ___enthusiasm about spending two weeks at Camp California in the U.S.A.