The reason for his success is ______ he worked very hard.
| A．why | B．that | C．whether | D．how |
------ I don’t think he is fit for the job, ______?
------Why do you think so ?
| A．do I | B．don’t I | C．is he | D．isn’t he |
______ is of great importance now , my teacher often reminds me ,is study.
| A．It | B． As | C．What | D．Which |
Although he was in poor health , Robert succeeded ______ other more famous engineers failed.
| A．which | B．that | C．what | D．where |
Even if the treatment _____, there’s still no magic pill for patients in the late stage of AIDS.
| A．does | B．performs | C．works | D．runs |
I’m afraid we can’t come, but thanks for the invitation_________.
| A．otherwise | B．somehow | C．anyway | D．therefore |