There are many buses running in the street. Don’t go ______ it.

Listen! David is talking happily with his mother in the next room.　— It ______ be his mother. She has gone to Yunnan to be a volunteer doctor.

Tim was so tired this morning. It was difficult to _________ of bed.

The old man wouldn’t stay at home for a rest even if it rained. —- . He would feel sick if he stayed home for one day.

What happened _______ you? You don’t look fine.—I have a cold.[ ]