I can __________ be a doctor. I don’t have enough patience at all.

A．seldom

B．ever

C．always

D．never

_________ should not be allowed to go out at night.

A．Twelve-years-old

B．Twelve-year-olds

C．Twelveyearold

D．Twelveyearsolds

He wants to be an actor _____it’s an exciting job.

A．and

B．so

C．because

D．why