_____ private cars bring us convenience, they also cause more traffic accidents and pollution.
A．While B．As C．If D．Since
______ around the Water Cube , we were taken to see the Bird’s Nest for the 2008 Olympic Games.
A．Having shown B．To be shown C．Having been shown D．To show
Her book didn’t ____ children probably because she employed too many scientific terms.
A．appeal to B．apply for C．intend for D．refer to
After years of research, he found the key ____ differences between species.
A．to explain B．to explaining C．of explaining D．explaining
--- Do you know Anna’s telephone number?
--- ______. As a matter of fact, I don’t know any Anna, either.
A．I think so B．I hope so C．I’d rather not D．I am afraid not
I have two elder brothers, ____ in the army for ten years.
A．the elder of whom served B．the older having served
C．the older of which served D．the elder one has served
