When the millionaire was young, he was very poor. Only by doing part?time jobs during the summer holiday ________ afford to pay his college fees.

A．he could B．could he

C．can he D．he can

—How unhappy your roommate looks!

—Yes, but he's not willing to tell me what it is ________ is troubling him.

A．what B．which

C．as D．that

The smoggy weather has made us realize ________ terrible problems we are faced with.

A．how B．what

C．that D．which

Nothing that you say can change his mind, ________？

A．do you B．don't you

C．can it D．can't it

—Which one of these two dictionaries do you advise me to buy, Oxford or Longman?

—Well, take Oxford. I think it is the ________ of the two.

A．best B．better

C．good D．well

(2013·江西高考)When I was a child, I ________ watch TV whenever I wanted to.

A．should　　　　　　　　　　 B．could

C．must D．need

(2013·湖南高考)He ________ sleep, although he tried to, when he got on such a hunt for an idea until he had caught it.

A．wouldn't B．shouldn't

C．couldn't D．mustn't

(2012·全国卷Ⅱ)I'm going to Europe on vacation together with John if I ________ find the money.

A．can B．might

C．would D．need

(2013·重庆高考)—What are you doing this Saturday?

—I'm not sure, but I ________ go to the Rolling Stones concert.

A．must B．would

C．should D．might

(2013·安徽高考)It ________ be the vocabulary that caused you the problem in the exercise because you know a lot of words.

A．may B．couldn't

C．should D．needn't