____ the problem of method is solved, talking about the task is useless.
| A．Until | B．Since | C．After | D．Unless |
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 |