______ birds have come back because the environment here becomes better and better．（ ）
| A． |
Thousands of |
| B． |
Thousand of |
| C． |
Thousands |
There were many people over there．He asked ．（ ）
A．what happenedB．what was happened
C．what did happen
She is poor afford the expensive suit．（ ）
A．so，thatB．enough，toC．too，to
He the city since he graduated from college．（ ）
A．has leftB．left
C．has been away from
﹣Thanks for cleaning the room，boy．
﹣ ．In fact，it's my to do so．（ ）
A．Not at all，dutyB．All right，work
C．OK，job
The mobile phone sells for ¥ 5，000，it is much more than its real ．（ ）
A．costB．valueC．price