________ him not to do so, he wouldn't have made such a serious mistake.
| A．If I persuaded | B．Did I persuade |
| C．Had I persuaded | D．If I should persuade |
I don’t think ____ possible to master a foreign language without much memory work.
| A．this | B．that | C．its | D．it |
Is ____ necessary to complete the design before National Day?
| A．this | B．that | C．it | D．he |
I hate _______ when young people speak to the elderly in a rude way.
| A．this | B．that | C．it | D．one |
—How long are you staying there?
— _____depends.
| A．It | B．Anything | C．This | D．Everything |
______was known to them all that William had broken his promise______ he would give each of them a gift.
| A．As, which | B．What, that | C．It , that | D．It , which |