A great many trees have been planted in the last few weeks.

12. priceless=invaluable adj. 贵重的，无价的

worthless=valueless=useless 无价值的

I think your advice priceless=invaluable.

These old papers are worthless=valueless=useless.

13. recover ①vt. =regain

I'm slowly recovering my strength after a flue

The man has recovered what was lost.

②vi. = from

Trade soon recovered from the effects of the war.

He has recovered from the strain of the exam.

③ n. recovery

14. They contain a harmful chemical that caused my liver to fail.

1) contain =have sth. inside it/ or as part of it v. 容纳，包含（全部或部分），含有（内容或成分）

The theatre can contain 4000 people.

That box contains old letters.

The book contains 40 maps, including that of the China.

Sea water contains salt.

2） cause sb. sth = cause sth. to /for sb.

cause sb. to do

The bad weather is causing problems for many farmers.

Her bad behavior has caused a great deal of anxiety for her family.

My little son has caused me a lot of trouble.

What caused him to change his mind so quickly?

. 15. match n. sth that is suitable or combines well with sth else 相配着，配对物

The sofa is a perfect match for the grey curtain in our sitting-room.

The cap is a match for the coat.

16. dangerous 表会对他人造成危害

　　in danger (of...) 本身处于危险中

The picture matches the story.

Some animals are in danger of dying out.

17. advice un

a piece of advice

ask sb. for advice

give advice on 就......提出建议

follow / take one's advice

she gave me some advice on how to get on well with classmates.

The doctor's advice is that my uncle (should) give up both smoking and drinking.

b) advise sth. /doing

Sb. (not )to do

( Sb. ) object-clause (should ) do sth.

He advised an early start.

starting early.