Nelson Mandela devoted all his life to the struggle of the African people and of every nation that seeks freedom．
| A．it | B．one | C．those | D．that |
We all thought that Betty could have run _______ if she had worn the sports-shoes that day.
| A．even faster | B．more slower | C．much quickly | D．still fastest |
In that traffic accident last night the man who hit five people in a row had drunk so much that he could no longer_______ between fantasy and reality.
| A．distinguish | B．disguise | C．disturb | D．disgust |
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 |
Mr. Bryan is a/an _______ secretary in our office, for he is able to do tasks successfully, without wasting time or energy.
| A．effective | B．efficient | C．flexible | D．sufficient |
There was enough evidence to prove that the explosion in Robinson’s house _______ the leak of natural gas.
| A．resulted in | B．resulted from | C．led to | D．contributed to |