【解释】

set off "出发"，侧重于去某个地方。

set out "出发，开始"，侧重于开始做某事，还有规划，展现的意思，后加不定式。

set about "开始，着手"，与set out意思相近，后加v-ing形式。

【练习】用set off，set out，set about的适当形式填空。

1). They succeeded in what they had _______ to do.

2). Having made up his mind, he _______ carrying out the plan.

3). If you want to catch that train we' d better _______ for the station immediately.

Ⅱ.词性变化 （旨在提供语法填空所需材料）

1. mercy n.仁慈，宽容 merciful adj. 宽恕的 merciless adj.残忍的；无情的

2. abrupt adj.突然的，意外的；唐突的，鲁莽的 abruptly adv.突然地；粗鲁地

3. expect vt. 期待，预期，

指望 expectation n. 期待，预料，指望，展望 unexpected. adj. 想不到的，未预料unexpectedly adv. 出乎意料地，想不到地

4. freeze v.(使)冻结，(使)

结冰 n.冻结；冰冻期 freezing n. 冰点

adj. 冰冻的，严寒的 /

5. practise vt.&vi. 实行；

练习；实习 practice n. 练习，实习，实践，习俗 practical adj.实际的，实

践的，实用的

【练习】用括号内所提供词的适当形式填空。

1). This result was beyond my wildest ________ (expect).

2). She was subjected to the ________ (mercy) criticism of her opponents.

3). They asked her to be ________ (mercy) to the prisoners.

4). We must put our plans into ________ (practise).

5). Your invention is very ________ (practice).

6). The young girl practices ________ (play) the violin every day.

7). His father died _______ (expect), and it was ten years since they were last together.

8). We were _______ (freeze) cold in the tent last night.

9). Our conversation came to an _______ (abruptly) end when George burst into the room.

Ⅲ.重点词汇（旨在提供词汇综合运用所需材料）

1. distinguish 辨别；辨认；（常与from, between连用）区别；区分

[典例]

1). I can distinguish them at a distance. 从远处我能认出他们。

2). The man distinguishes himself by his wisdom这个人因智慧而扬名。

[重点用法]

distinguish A from B 辨别A与B be distinguished from不同于......

be distinguished by 以......为特征 be distinguished for 因......而著称

distinguish oneself 显扬自己；使自己扬名