另外，有些名词通常只用复数形式，如：fundamentals(基本原则)，goods(货物)， means(方法)， rapids(急流)，shorts(短裤)， sweets(欢乐)， valuables (贵重物品)。

三、同步练习(Correct errors， if any，in the following sentences：)

1. The scholars met once a year to exchange esperiences.

2. Foreign ship are not allowed to fish in our territoral water.

3. I went to the doctor for an advice about my health.

4.The letter contained an important information.

5.In the afternoon I did some baby-sittings，for it is a fun looking after children.

6.The congregation was not numerous that night，but they seemed to be listening attentively to my lecture.

7.Poultries are dear in the city.

8.The board of director is shaking heads at the chairman‘s speech.

9.The merchandises have arrived undamaged.

四、答案

1. The scholars met once a year to exchange esperience.

2. Foreign ship are not allowed to fish in our territoral waters.3. I went to the doctor for an advice about my health.

4.The letter contained an important piece of information.

5.In the afternoon I did some baby-sittings，for it is fun looking after children.

6.The congregation were not numerous that night，but they seemed to be listening attentively to my lecture.

7.Poultry are dear in the city.

8.The board of directors are shaking heads at the chairman‘s speech.

9.The merchandise have arrived undamaged