Biology is ____
| A．science of life | B．science of the life | C．the science of the life | D．the science of life |
They desired that they_______ the right to vote.
A．had |
B．have | C．are | D．were |
The professor explained this theory so clearly that this phenomenon was easy enough ________.
| A．for us to work out | B．working out |
| C．for working out | D．to working out |
—Mike, our team will play against the Rockets this weekend. I am sure we will win.
—_________.
| A．Congratulations | B．Cheers | C．Never mind | D．Good luck |
He has devoted himself __ mankind.
to benefit B. benefiting C. to benefiting D. benefited
Robert is said ____ abroad, but I don’t know what country he studied in.
| A．to have studied | B．to study | C．to  be studying |
D．to have been studying |