In summer milk will quickly turn sour ________ it is put into a refrigerator．

though

unless

because

once

Unfortunately my car broke down and I was stuck here while it ________．

repaired

was repairing

would be repaired

was being repaired

Good news! The price of all those second-hand goods is ________ before．

30％ as lower as

30％ lower than

lower 30％ than

as 30％ low as

The professor entered the room and seated himself in a chair, ________ for answering questions．

prepared

preparing

having prepared

being prepared

Thank you for sending us ________ fresh vegetables．You have done us ________ great service．

不填; the

the; a

不填；不填

the; 不填

The T-shirt was a little bit small for him, so he changed it ________ a larger one．

with

from

by

for

________ there is life on another planet, most scientists believe, is almost impossible．

Whether

What

That

How

Many farmers in the countryside have gone to cities to look for work and left their children behind ________ by their grandparents．

to be raised

raised

being raised

raising

________ at the top of the Oriental Tower, people below will look very small．

Stand

Standing

To stand

If you stand

The town, ________ thousands of travelers visit every year, is known for its stone bridge and beautiful rivers．

which

that

where

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