____ I'm mistaken, I've seen that tall man at a party before.
| A．If | B．As | C．Unless | D．When |
When ______ comes to research into heart disease and its effects on the body, we do not have adequate substitutes for the use of animals.
| A．it | B．this | C．that | D．which |
Environmental experts point out that ______ some serious problems such as global warming, but it also could threaten human life.
| A．not only does increasing pollution cause |
| B．not only causes increasing pollution |
| C．not only increasing pollution causes |
| D．not only increasing pollution does cause |
—I heard that Mr. Smith has become a triathlete.
—Oh, really? He has become ______ he wanted to be.
| A．who | B．which | C．what | D．that |
China Mobile, which has cut its charges in recent years, is desperate to find new income sources ______ its traditional services.
| A．including | B．other than |
| C．beyond | D．rather than |
The stars are so hot that they ______ great light and heat — more than the hottest, brightest fire you can imagine.
| A．give away | B．give in | C．give up | D．give off |