How many women doctors are there in your hospital?
___________ them _________over thirty．（ ）
| A． |
A number of；are |
B． |
The number of；are |
| C． |
The number of；is |
D． |
A number of；is |
Who will you ask to help with the work，Lucy or Lily？﹣Lily．She is much ________．（ ）
| A． |
careful |
B． |
more careful |
C． |
most careful |
Must I clean the room now？
No，you ________．You can do it later．（ ）
| A． |
needn't |
B． |
can't |
C． |
may not |
There's little ________ left at home．Go and buy some，dear．（ ）
| A． |
carrots |
B． |
potatoes |
C． |
rice |
How long can I keep this dictionary？
Two weeks．You must ________ it on time．（ ）
| A． |
collect |
B． |
call |
C． |
return |
The 31 stOlympic Games will take place ________ August，2016．（ ）
| A． |
in |
B． |
on |
C． |
at |