All Mrs Smith's efforts to tidy the room were _____ because her grandson soon made a mess of it again.
| A．at all costs | B．at random |
| C．in vain | D．in return |
The patient will have to remain in hospital for another week ____ the recent medical report.
| A．on behalf of | B．on the basis of | C．on the side of | D．on top of |
Studying alone, you are free to choose what to learn and when, ________ you don’t need others’ agreement.
| A．while | B．if | C．though | D．as |
—Why did you drop the chance of earning big money?
—________. You know, I don’t want to get rich by taking risks.
| A．All is well that ends well | B．One man’s meat is another’s poison |
| C．Better safe than sorry | D．No sweet without sweat |
. Some experts are warning that the step the US government has taken to deal with the current crisis is ______ of much risk.
| A．ones | B．one | C．that | D．those |
After the adjustment of financial policies, many netizens put up posts, 90 percent _______ carried the message of approval.
| A．of which | B．of whom | C．of them | D．of what |