In America, if ________ friend has invited you to drop by anytime, it is ________ best to call before visiting to make sure it is convenient for him.
| A．a; a | B．the; a | C．a; 不填 | D．the; 不填 |
Beijing government puts more than 700 million yuan to increase its green space this year; ____________ doubles the money provided last year.
| A．as | B．while | C．that | D．which |
I can guess you___________ your sweater inside out.
| A．had worn | B．wore | C．are wearing | D．were wearing |
It is only when you nearly lose someone ____________ you fully realize how much you value him.
| A．do | B．then | C．will | D．that |
--I'm going downtown. --Come on. __________.
| A．I'll give you a lift | B．You are welcome |
| C．Don't do that | D．Come with me |
--Shall Mary come and play computer games?
--No, __________ she has finished her homework.
| A．when | B．if | C．unless | D．once |