生产。

2) Before the lecture, the professor is used to testing out the whole experiment. 上课前，这个教授习惯先将整个实验试验一番。

[短语归纳]

test on sb./sth. 在......(身上)做实验/试验

have/take a test in 参加......考试

2. ring up 打电话给......

[短语归纳]

ring back 回电话

ring off 挂断电话;停止讲话

ring a bell 唤醒经常是模糊的记忆

[典例]

1) I have to ring off now because my friend is waiting for me. 我朋友在等我，我得挂电话了。

2) On arriving at the airport, he rang up his mother to say everything was ok. 一到达机场，他就打电话给他母亲报平安。

3. turn around 转向

[典例]

1) He heard a voice but when he turned around, he saw nobody. 他听到声音，但转身却没发现有人。

2) As he walked towards the hotel, he suddenly turned around and found an old lady following him. 当他朝旅馆走去时，突然转身发现一个老妇人跟着他。

[短语归纳]

turn away 把(脸)转过去

turn against 背叛,反抗

turn on/off 打开/关掉

turn up 出现/调大(音量)

turn down 拒绝,调小(音量)

turn out 结果是;证明是

4. leave...alone 不打扰

[短语归纳]

leave behind留下,遗留

leave aside(把某事)搁置一边

leave for出发前往

leave out省去,遗漏,不考虑

[典例]

1) Leave him alone and he will produce. 别打扰他，他会写出来的。

2) He was asked to leave for another city in 24 hours. 他被要求24小时内离开到另一个城市去。

3) The teacher required us to leave out some unnecessary words in our essays. 老师让我们将论文中不