Historical experience can as a most important source of information.
| A．serve | B．use | C．regard | D．prove |
18. It was ______ back home after the experiment.
| A．not until midnight did he go | B．until midnight that he didn’t go |
| C．not until midnight that he went | D．until midnight when he didn’t go |
17. -- My mother always tells me to try my best _______ many difficulties.
-- I can’t agree any more. _______ you put your heart into work, you can overcome them.
| A．because of / As far as | B．due to / As soon as |
| C．in spite of / As long as | D．despite of / As much as |
16. Charles Babbage is generally considered _______ the first computer.
| A．to invent | B．inventing | C．to have invented | D．having invented |
15. __________ made his mother worried.
| A．The child was addicted to playing computer games |
| B．The child’s being addicted to playing computer games |
| C．The child’s being addicted to play computer games |
| D．The child addicted to playing computer games |
14. His careless driving _________ the traffic accident. That is, the traffic accident was ______
his careless driving.
| A．resulted in / due to | B．led to / thanks to |
| C．resulted from / because | D．contributed to / as a result |