Mr. Andrew taught his students how to develop the basic skills in the physics class, ______ everything through jokes and experiments.
| A．to explain | B．explained | C．explaining | D．explains |
Whenever I go to Beijing, ____ is quite frequent, I will go to visit the Great Wall.
| A．where | B．which | C．as it | D．It |
The two boys fought and fought until one ______.
| A．gave up | B．gave in | C．gave | D．gave off |
He will _____ our class to sing at the school singing contest.
| A．take place of | B．stand for | C．represent | D．representative of |
John _____ knowledge of radio just by staying around the radio station.
| A．caught on | B．worked up | C．took up | D．picked up |
It isn't so much whether he works hard; the question is whether he works _____.
| A．above all | B．in all | C．at all | D．after all |