1. He has left his book here on _____, so that you can read it.
A. purpose B. intention C. aim D. meaning

[答案]A. purpose.
[注释]on purpose 是介词习语，意为“故意地”。如用intention,则应说by intention 故意地。

2. The magician picked several persons from the audience and asked them to help him with the performance.
A. by accident B. on occasion C. at random D. on an average

[答案]C. at random.
[注释]at random(=without aim or purpose)随便地，胡乱地：His clothes were scattered about the room at random.
By accident 意外地；on occasion 偶尔；on an average 平均计算。

3. The open university was started in order to help those who _____ having a university education when they were young.
A. stopped B. failed C. missed D. ceased

[答案]C. missed.
[注释]miss doing sth.没有做某事：I missed seeing the film when it was shown at school.(学校放映那部电影时，我没有能去看。)

4. His _____of the aeroplane was correct in every detail and could really fly.
A. shape B. pattern C. design D. model
[答案]D. model.
[注释]model 此句中意为“（飞机的）模型”。

5. If you _____ your demand, then maybe you will have more chance of getting what you want.
A. conduct B. dismiss C. grant D. moderate

[答案]D. moderate.
[注释]moderate(=make or become less violent or extreme)节制，缓和，减轻。