So far, no agreement ________ on which type of exercise is best suitable for keeping fit.

I would have helped you, but I ________ really occupied the whole week．

 “Do you know that Jack ______ a postman for about six years?” “Yes, I see.”

All possible means ____ to prevent the air pollution, but the sky is still not clear. 

Mike wasn’t at home yesterday. He ______to give us a lecture.