6. He is quite sure that it’s impossible for him to finish the task within two days.
| A.extremely | B.absolutely | C.very | D.particularly | 
Susan, _____ university student from European, teacher me _____ art in he spare time.
| A.an; / | B.a; the | C.an; the | D.a; / | 
—Catherine, I have cleaned the room for you.
 —Thanks, you __________it. I could manage it myself.
| A.needn’t do | B.needn’t have done | 
| C.mustn’t do | D.shouldn’t have done | 
The boy wanted to ride his bicycle in the street, but his mother told him___________.
| A.not to | B.not to do | C.not do it | D.do not to | 
There is nothing wrong with using a credit card for purchases. It’s more _______ than carrying loads of cash.
| A.convenient | B.valuable | C.sensitive | D.innocent | 
Cathy is taking notes of the grammatical rules in class at Sunshine School, where she ______ English for a year.
| A.studies | B.studied | 
| C.is studying | D.has been studying |