rare, adj, 罕见的；稀有的；rarely, adv, 很少；难得；rareness, n, 稀有；珍奇；（空气等的）稀薄

拓展：

表示频率的副词：always总是，usually 通常，frequently/ often经常，sometimes 有时，occasionally 偶尔，seldom/ rarely 很少，never 从不

Practice

Rewrite the following sentences without changing the meaning.

1. I have rarely seen such a beautiful sunset.

____ ____ ____ seen such a beautiful sunset.

2. He is rarely ill. ____ ____ ____ ill.

Key for reference

1. Rarely have I

2. Rare is he.

4. toothache n.[c, u] pain in a tooth or teeth. 牙痛

e.g.

I've got a toothache.我牙痛。

He had a bad toothache.他的牙痛得厉害。

构词解析：

ache (n) 疼痛，和表示身体部位的单词结合构成复合词，例如：

a headache头痛，(a) toothache 牙痛，(a) backache 背（腰）痛，(an) earache 耳痛，(a) stomachache 胃痛

Practice

Put these sentences in the right order to make up a dialogue.

A. P: I must see the dentist（牙医）now, nurse.

B. N: I'm afraid he can't. Can't you wait till this afternoon?

C. P: That's very late. Can the dentist see me now?

D. N: The dentist is very busy at the moment. Can you come at 2. p.m.?

E. P: I can wait, but my toothache can't!

1. _____ 2. ______ 3. _______ 4. _______ 5. _______

Key for reference

1. __A___ 2. __D_ 3. __C__ 4. ___B__ 5. __E___

5. unhealthy adj. not having or not showing good health；harmful to health不健康的；有害健康的。

e.g.

That is an unhealthy diet. 那是不健康的饮食。

The air in this area is unhealthy for people.这地区的空气对人们的健康不利。

构词解析：

unhealthy. adj. 不健康的; health. n [u] 健康; healthy. adj.健康的

Practice

Complete the following sentences

1. They are well fed so they are very _______. (健康的) .

2. My grandmother enjoys good _______（健康）though she is over 80.

3. Many children in this village look thin, pale and ________.（不健康的）

Key for reference