A single pipeline ___________ all the houses with water.
| A．is served | B．serves | C．are serving | D．serve |
--- Is it true that Mike refused an offer from Yale University yesterday?
--- Yeah, but I have no idea _______ he did it; that’s one of his favorite universities.
| A．when | B．why | C．that | D．how |
Group activities will be organized after class _______ children develop team spirit.
| A．helping | B．having helped | C．helped | D．to help |
--- I spent two weeks in London last summer.
--- Then you must have visited the British Museum during your stay,you?
| A． | mustn't | B． | haven't | C． | didn't | D． | hadn't |
We'll reach the sales targets in a monthwe set at the beginning of the year.
| A． | which | B． | where | C． | when | D． | what |
James has just arrived, but I didn’t know he _______ until yesterday.
| A．will come | B．was coming | C．had come | D．came |