Father______for London on business upon my arrival，so I didn't see him．
| A．has left | B．left | C．was leaving | D．had left |
Life is like __________ ocean; only __________ strong-willed can reach the other shore.
| A．an; the | B．the; a | C．the; / | D．/; a |
--- Kim, give me your report by 1O am.
--- __ have you been in charge of this project?
| A．Since when | B．By whom |
| C．For what | D．From where |
–What’s that noise?
–Oh, I forgot to tell you. The new machine ______.
| A．was tested | B．will be tested |
| C．is being tested | D．has been tested |
A number of books in the library _______ been stolen so that the number of them ______smaller than before.
| A．have; is | B．has; is | C．has; are | D．have; are |
The growing speed of a plant is influenced by a number of factors, _____ are beyond our control.
| A．most of which | B．most of them |
| C．most of what | D．most of that |