7. set sail for sp. 启程去某地 have / take a sail

轮船启程去非洲。 我们返航了。

他们绕岛进行了一次航行。They took/had a sail around the island.

sail vi. 航行，起航 他喜欢去航海 He likes go sailing.

船何时起航？When does the ship sail? 船沿着海岸航行。The ship sailed along the coast.

他已乘船去纽约了。He has sailed for/ to New York.

8. gold/golden

9. by the 1920s , he had become an explorer, searching for the ...

by: no later than or before

Mike must have made some friends in his school by now.

The new suspension bridge by the end of last month.

A. has been designed B. had been designed C. was designed D. would be designed

By the time (conj.) doctor arrived, the woman had given birth.

By the time (conj.) you get there, it will be dark.

10. preserve v. ①保护，维护 ~ ... from ...保护...以免...②保持，维持原状

我们必须保护视力。We must ~ our eyesight. 盐能防止食物腐烂。Salt ~s food from decay.

人类应保护森林。Man should ~ forests. 他设法保持住自己的独立性。He has managed to ~ his independence.

11. be known as/ for/ by/ to 可用well-known , famous 替换known 同义

Einstein was known for his Theory of Relative. Is he known as a poet or novelist?

The area is known as a green tea producing place. The town is known for its fine park.

The West Lake is known as the paradise on earth. A person is known by the company he keeps.

It is known to all that theory comes from practice.= As is known to all, theory comes from practice.

12. riches n. 财富 Riches have wings.

works sands manners arms times papers seas goods means

13. empty v. &adj.

我向教室里看了看，但发现里面空无一人。I looked into the classroom but found it empty.

她把包里的书都拿出来了。She emptied the bag of the books.

14.present ①adj.出席，到场（做表语或后置定语）；现在，目前（做前置定语） ②n. 礼物；目前，现在

be present at be present in at present for the present

All the people at the party were his supporters.

A. present B. thankful C. interested D. important

Oxygen is present in the air. How many people were present at the meeting?

In the present case, we can do nothing but wait. He is in Shanghai at present.

I can't remember it for the present. I buy it for a present. They exchange presents at Christmas.

15. fall ill with a fever be ill with

16. die of 因...而死,死于疾病，情感，饥寒，年老等原因

die from 因...而死,死于除了疾病，情感，饥寒，年老等原因以外，尤指环境，事故等

die for为...而死； die out（物种）灭绝（风俗）消失 ；