Although medical science________control over several dangerous diseases，what worries us is that some of them are recurrent.
| A．achieved | B．has achieved |
| C．will achieve | D．had achieved |
My parents were quarrelling about me ____ I could not quite tell why．
| A．since | B．though | C．if | D．until |
A dozen ideas were considered____the chief architect decided on the design of the building．
| A．because | B．before | C．whether | D．unless |
—It’s a top secret．
—Yes, I see．I will keep the secret _____you and me．
| A．with | B．around | C．among | D．between |
Speaking of all the songs he has written, I think this is probably his____one.
better-known B. well-known C. best-known D. most-known
After two years’ research, we now have a ____ better understanding of the disease.
| A．very | B．far | C．fairly | D．quite |