—Mary, let’s go to the bookshop this weekend. Will you be ______?
—Sorry, but I’m going to visit my uncle in the countryside.
| A．vacant | B．suitable | C．convenient | D．available |
____ Helen’s knowledge and vocabulary expanded, she asked more and more questions.
| A．When | B．While | C．As | D．Before |
I didn’t know I was spelling a word or even ____ words existed.
| A．that | B．what | C．which | D．one |
In a way, Pompeii is like a time capsule ____ a frozen moment in history.
| A．protecting | B．preserving | C．preventing | D．protesting |
By the time some scientists ____ the lost towns, they ____ an awesome historical site.
| A．had found, had found | B．found, found |
| C．found, had found | D．had found, found |
He constantly gets into awkward and absurd situations, ____ audience can be greatly amused.
| A．which | B．where | C．that | D．what |