“Where did you find the professor who made the speech yesterday?” “It was in the hall _________ the students often have a meeting.”

       hard you try, it is difficult to lose weight without cutting down the amount you eat.

单项选择（每题1分）In his letter was his promise _____ he would spend the Christmas Eve with me.

The man put out the cigarette when _______ that smoking was not allowed on the train.

When asked how he liked his job, he said he was happy _____ he was．