I began to teach ________ English when I was twenty-two years old.
| A． |
they |
B． |
their |
C． |
theirs |
D． |
them |
Would you like to join me in making cakes tomorrow？
______．（ ）
| A． |
It doesn't matter． |
B． |
Don't worry． |
| C． |
You're welcome． |
D． |
I'd love to． |
Professor Tu Youyou never stops doing research on Chinese medicine，______？（ ）
| A． |
is she |
B． |
does she |
| C． |
isn't she |
D． |
doesn't she |
The two companies decided to work together ______ they had common interest．（ ）
| A． |
because |
B． |
unless |
C． |
but |
D． |
or |
______ I park my car here for a while？
No，you mustn't．Do you see the sign"NO PARKING"？（ ）
| A． |
Would |
B． |
May |
C． |
Must |
D． |
Should |
The workers are busy _______ windows to the new building these days．（ ）
| A． |
fix |
B． |
fixed |
C． |
fixing |
D． |
to fix |