Only after he realized the significance of mastering two languages ______ English carefully.
| A．did he set about learning | B．did he set out learning |
| C．had he set about learning | D．had he set out learning |
_____the climate changes so much has caused many discussions among the scientists.
| A．What | B．Which | C．When | D．That |
I tried more than once to persuade the taxi
driver to slow down,but he just ____listen.
| A．shouldn’t | B．mustn’t | C．couldn’t | D．wouldn’t |
I caught a bad cold the other day and my weekend ____.
| A．has ruined | B．had ruined |
| C．has been ruined | D．had been ruined |
Each time invited to a dinner,she always refuses, ____she has to take care of her baby.
| A．to say | B．saying | C．says | D．having said |
The victims of the domestic violence, _____were often silent in the past,now choose to
call for various help.
| A．ones | B．those |
| C．who | D．that |