John Snow was ____famous doctor in London—so expert that he attended ____Queen Victoria as her personal physician.

How did your mathematicsexam go—I thought I ，but in fact I fell behind in the class

One of the best ways for people to keep fit is to ______ healthy eating habits.

____ have known the truth, or shewould have told us.

Our new teacher is going to give us some ______ this term.