The students were ________ over the ________ problem，listening to the teacher with a ________ expression on their faces.

20. I got up early this morning, but I ________ so because I was not on duty today.

Many a time，the Chinese government urged that American government stop sellingadvanced weapons to Taiwan，but it__________ listen，__________Sino-US relations

___ she was invited to the lecture made her very happy.

What do you think of the film 2012?—Well, it’s not bad. At least it’s ________ the one I saw last week with Jean.[ ]