You’d better go there by train. The train ticket is __________the airplane ticket.
| A．as cheap three times as | B．as three times cheap as |
| C．three times cheaper than | D．cheaper three times than |
"We can’t go out in this weather," said Bob, ________ out of the window.
| A．looking | B．to look | C．looked | D．having looked |
Scientists are convinced _______the positive effect of laughter ______ physical and mental health.
| A．of ; at | B．by ; in | C．of ; on | D．on ; at |
Many of them turned a deaf ear to his advice, ________ they knew it to be valuable.
| A．as if | B．now that | C．even though | D．so that |
It is so difficult a question_______ none of the kids could work it out.
| A．as | B．that | C．which | D．X |
Kunming is called“Spring City”, but it _____ snow in winter.
| A．shall | B．can | C．must | D．might |