---I called you yesterday. A woman answered, but I didn’t recognize her voice.
----Oh, it _____ my aunt Jean.
| A．must be | B．must have been |
| C．might be | D．can have been |
—Now that you like computers very much, isn't that a good idea to get a ____?
—Well, I'd like to, but I can't afford such an expensive computer at present.
| A．one | B．them | C．it | D．that |
I have many friends, ____ some are businessmen．
| A．of them | B．from which | C．of who | D．of whom |
The car has been well maintained and is _____ excellent condition．
| A．in | B．under | C．on | D．with |
—Why was Professor Johnson unhappy those days?
—Can't you see it clearly? The only reason was that the theory he stuck to_____ wrong．
| A．proving | B．being proved | C．proved | D．was proved |
______ as the main reason for the recent world-wide economic problems is the fact that the US government would hardly accept.
| A．Regarding | B．To regard | C．Regarded | D．Being regarded |