We can never expect bluer sky unless we create less polluted world.
| A．a; a | B．a; the |
C．the; a | D．the; the |
-----______you received the news ?
------Last night .
| A．When was it that | B．When was it |
| C．When it was that | D．When it was |
My parents have promised to come to see me before I ____for Africa.
| A．have left | B．leave | C．left | D．will leave |
The doctor persuaded the patient ____.Which statement is WRONG?
| A．not to smoke again | B．to stop smoking |
| C．to stop to smoke | D．into stopping smoking |
Don’t forget to examine the test paper you have just finished
_____the possible mistakes in it .
| A．correcting | B．to correct |
| C．and corrected | D． having correcting |
The school _____you visited yesterday is the place ____I once learned .
| A．where; that | B．where; where | C．which; where | D．that; which |