long enough to have a job, I would choose to be a doctor, hose AIDSpatients．
| A．Had I lived, helping | B．If I should live, help |
| C．Were I to live, helping | D．IfI would live, helping |
John may phone tonight，I don't want to go out ______ he phones.
| A．in case | B．in that case | C．so that | D．in time |
He is always helping people without expecting anything ______.
| A．in need | B．in fact | C．in danger | D．in return |
I will mark ______ everything you say.It is helpful to the English learners.
| A．up | B．down | C．out | D．off |
—Believe me，all your efforts will ______ some day.
—Thanks for your encouragement.
| A．pay back | B．pay down | C．pay off | D．pay for |
Some blood types are quite common，others are regionally______，and still others are rare everywhere.
| A．distributed | B．contributed | C．obtained | D．convinced |