30．The extra room________very useful when we had visitors．
| A．had been proved | B．was proved |
| C．had proved | D．Proved |
In some countries, _____ are called “public schools” are not owned by the public.
| A．which | B．that | C．as | D．what |
—I’d like to invite you to my birthday party this evening.
—Thanks, but ____ I’ll have time I’m not sure at the moment.
| A．while | B．whether | C．if | D．when |
Determination is a kind of basic quality and is __________ it takes to do jobs well.
| A．what | B．that | C．which | D．why |
Is the hotel _______ offered you a job ________ you stayed the first time you arrived here?
| A．which ;where | B．the one ;in which | C．where ;that | D．the one that ;which |
—Nowadays the doctors are trying their best to reduce the people’s fear__________ they would be affected by the present disease called “Bird Flu （禽流感）”.
| A．whether | B．which | C．that | D．when |