“You must keep______ in the hospital,” the woman said to me ______ .

He is a          swimmer, and he swims very _____________ .

____ you are, _____ mistakes you’ll make.

—What do you think of the report about the air pollution on TV last night?—I think the situation is so        that we should take action to protect the environment.

I felt so __________that I fell __________in the History class this afternoon.