问题
Who helped Betty tidy up the bedroom just now—________. She cleaned it all by herself.
A:maybe you are right
B:maybe you should buy some new ones.
C:you should be glad
D:you should take a part-time job.;
B:maybe you should buy some new ones.
C:you should be glad
D:you should take a part-time job.;
正确答案是：
