—Can Professor Li be in the laboratory?—He ______ be; I saw him there half an hour ago.
The doctor __________ she sent her friend is very well known.
Do you know the factory, __________ products are of high quality?
Jim passed the driving test, __________ surprised everybody in the office.
I am going to meet Tom __________ they say is a good boy.
Ladies and gentlemen, please fasten your seat belts. The plane __________.