单项选择
1．Most of the students felt rather disappointed at the English party. They say that it ______ better organized.
A. had been B. had to be C. must have been D. could have been
2．I don't really work here; I ____ until the new secretary arrives.
A. just help out B. have just helped out
C. am just helping out D. will just help out
3．Staying up is bad _____ you , but getting up early is good _____ your health.
A. for, for B. to , for C. to, to D. for, to
4． You’ve switched the machine off. I told you not to,_____?
A.didn't I B.haven't you C. will you D. did I
5．___in the air, this kind of steel become harder and harder.
A. Cooling B.Having cooled C.Being cooled D.Cooled
