Principal White has been working in the school for about 20 years, ____all his energy to teaching and researching as well as the running of a healthy school.
| A．devoted | B．devoting | C．to devote | D．devote |
--- The light in the office is still on. --- Oh, I forgot _______.
| A．turning it off | B．turn it off | C．to turn it off | D．having turned it off |
“ Have you decided when ________?” “ Yes, tomorrow morning.”
| A．to leave | B．to be leaving | C．will you leave | D．are you leaving |
She pretended _______ me when I passed by.
| A．not to see | B．not seeing | C．to not see | D．having not seen |
There’re so many kinds of tape-recorders on sale that I can’t make up my mind _____ to buy.
| A．what | B．which | C．how | D．where |
—How’s your tour around the North Lake? Is it beautiful?
—It ________ be, but it is now heavily polluted.
| A．will | B．would | C．should | D．must |