第一节 语法和词汇知识（共15小题，每小题1分，满分15分）
1. Seeing everything________, the professor left the lab happily.
A.done B.did C.do D.doing
2.The meeting ______ tomorrow will be of great importance. All of us should attend it. A . held B.to be held C.being held D.is going to be held
