The boys, _______ _had played the whole day long, were tired.
| A．all of what | B．all of which | C．all of them | D．all of whom |
I don’t think the experiment is ______ failure, because it has provided us with _____ valuable experience for our future tests.
| A．不填; 不填 | B．a; 不填 | C．a ; a | D．不填; a |
____ you know your potential（潜力）, you have to rely on many other people to get to where you are.
| A．While | B．Since | C．If | D．Where |
It was not until Maggie had arrived at her office _____ her appointment with the doctor.
| A．did she remember | B．had she remembered |
| C．when she remembered | D．that she remembered |
When _____ my childhood, I get lost in happy memories of times now gone forever.
| A．looking out for | B．looking forward to |
| C．looking back on | D．looking down on |
----- Now that you like the portable personal computer so much, why not buy one? It is of great use to your work.
---- Well, I can’t afford _____ computer at present．
| A．a such cheap | B．so expensive a |
| C．so an expensive | D．so cheap |