The public transport system in Beijing is very good now, so there _____be any difficulty in traveling around the city.
| A．couldn’t | B．mustn’t | C．needn’t | D．shouldn’t |
28. ____well prepared you are ,you still need a luck in mountain climbing .
Helping others is a habit，______you can learn even at an early age.
A it B. that C. what D. one
You can make a complaint to the local government ___ you are happy with the way they deal with the matter.
| A．unless | B．if | C．once | D．as |
The patient looks much better .
-------_____is it that has made him ____he is today ?
| A．what ; that | B．That ; that | C．What;which | D．What;what |
--How much do you know about the 3D film technology?
--A little. Not until ____the hot movie Avatar ____some about it.
| A．did I see ,did I begin to learn | B．I saw, I began to learn |
| C．I saw, did I begin to learn | D．did I see, I began to learn |