Once_____in the forest, you ought to remain__you are waiting for help．

admit that there are still someproblems about NMET, we don’t mean that it’s of no use

Rising evidence suggests that the use of the vaccines(疫苗)will be effective tothe spread of common cold.

Helen, can I wear a T-shirt and jeans to the evening party —OK. But a dress might be___________.

Shall we go to see a film tonight —________________.