Scientists say it may be five or six years _______ it is possible to test this medicine on human patients.
| A．since | B．after | C．before | D．when |
— Since you’ve agreed to go, why aren’t you getting ready right now?
— But I ______ that you would like me to start at once.
| A．don’t realize | B．haven’t realized | C．didn’t realize | D．hadn’t realized |
— Is that the small town you often refer to?
— Right, just the one ______ you know I used to work for years.
| A．that | B．which | C．where | D．what |
______ permission to hold a party at home, Mary started to write invitations to her friends.
| A．Giving | B．To be given | C．Having given | D．Having been given |
— Excuse me, sir, could you tell me how to go to the City Hall?
— Sorry, I’m a new comer. You have to ask, I’m afraid, ______ is a native.
| A．someone | B．whoever | C．who | D．whomever |
The villagers were warned ______ the water from the river polluted by the chemical works..
| A．to drink not | B．drinking not | C．not to drink | D．not drinking |