The drug came under strong attack from _______ professional observers, who had been backed up by many doctors.
| A．confused | B．confusing | C．concerning | D．concerned |
Look! Here come the dark clouds. It______ rain.
| A．will | B．would |
| C．is going to | D．was going to |
______ fast did John run ______ I could hardly catch him.
| A．So; / | B．Such; that |
| C．As; as | D．So; that |
It’s known to us all that the deeper you dive, ________ you can breathe.
| A．the difficult | B．more difficult |
| C．most difficult | D．the more difficult |
It’s the third time _____ arrived late this month.
| A．that you | B．when you |
| C．that you’ve | D．when you’ve |
The Golden Gate Bridge, _______ several hundred years ago, is worldwide famous.
| A．which is built | B．built |
| C．having built | D．which built |