Let’s stop _________ and _________ a rest．

to work; having

working; having

to work; to have

working; to have

They agreed to the plan which _________．

sounded good one

is a good one

sounded good

is good sounds

I’m sorry I _________ your lecture yesterday, but I _________ busy recently．

missed, have been

miss, am

had missed, was

have missed, had been

If he _________, don’t interrupt him．

still works

is still working

still had been working

will still be working

I’ve bought an English dictionary which you can _________ if you meet new words．

get to

come to

refer to

look up

Susan, _________ university student from Europe, teaches me _________ art in her spare time．

an; 不填

a; the

a; 不填

an; the

We were going to go out, but _________ watching TV at home because of rain．

took up

came out

set out

ended up

In my view, biology is _________ chemistry, but a little easier than mathematics．

a subject so difficult as

as difficult a subject as

as a difficult subject as

difficult as subject as

It is said that by no means _________ to get into this laboratory without Mr．Jackson’s permission．

can the students be allowed

the students can be allowed

can be the students allowed

can be allowed the students

Since the earthquake hit Japan, suggestions for detecting the radiation materials have been _________．

put up

put away

put forward

put out