He made another wonderful discovery, _______________ of great importance to science.
| A．which I think is | B．which I think it is | C．which I think it | D．I think which is |
I’ve heard that we will set out _________ the morning of Dec 25th .
| A．at | B．in | C．on | D．over |
— Remember the first time we met, Jim?
— Of course I do. You _______ in the library.
| A．were reading | B．had read | C．have read | D．read |
_______ has recently been done to provide more buses for the people, a shortage of public vehicles remains a serious problem.
| A．That | B．What | C．Despite what | D．Though what |
There are many other examples _______ the development of Chinese writing.
| A．reflect | B．which reflecting | C．reflecting | D．reflected |
Listen! His family must be quarrelling, _______?
| A．mustn’t it | B．isn’t it | C．aren’t they | D．needn’t they |