His health _____under the pressure of work and he had to stay in hospital for a month. [ ]

When I was passing by, I saw them ________ at the nursery.

You are not supposed to get off the bus________ it stops.

In my opinion, all Mr Li ______ good to his students in his class at present. He is very strict with them in their studies.

The UN Climate Change Conference inCopenhagen was held in a tense ______ due to lack of deep understanding.