Nowadays, most people，in order to keep fit，prefer walking to driving ____necessary.
| A．if | B．unless | C．in case | D．as if |
The government is trying to reduce people’s fear _________ they are likely to be affected by the nuclear radiation.
| A．whether | B．what | C．that | D．how |
Their house ______ mine in having no garage.
| A．different from | B．differs from | C．differs | D．differs with |
I _______ my success to my family’s support.
| A．devote | B．contribute | C．refer | D．owe |
It is _________ pleasant to take a crowded bus.
| A．by no means | B．by means of | C．by all means | D．by any means |
It is uncertain _______ side effect the medicine will bring about,although about two thousand patients have taken it.
| A．that | B．what | C．how | D．whether |