17．mass adj.大规模的；数量极多的；n.一团，一堆；许多；(物理)质量

18．sickness n．疾病；恶心，呕吐

sick adj.有病的，恶心的

19．symptom n．症状；征兆

20．bleed vi.流血，失血

blood n．血

Ⅱ.短语自测

1．focus_on集中于......

2．open_up打开；开拓；开业

3．in_the_form_of以......形式

4．carry_out执行，实施

5．try_out测试，试验；参加选拔

6．in_large_quantities大量地

7．pick_out挑选

8．by_accident意外地

Ⅰ.阅读课文，选出最佳答案

1．Which of the statements is WRONG according to the passage?

A．Aspirin and penicillin have saved millions of people's lives.

B．Aspirin was invented in 1897.

C．Aspirin was made from a chemical.

D．Chewing on leaves will have the same effect as taking aspirin.

答案　D

2．Aspirin can not only prove vital for reducing fever and helping stop pain, but also ________.

A．reduce the risk of having bad colds

B．reduce the risk of heart attacks

C．reduce the risk of all cancers

D．cure all the people with diabetes

答案　B

3．Which statement is TRUE according to the passage?

A．Aspirin can prevent strokes.

B．Aspirin can help all the people with heart disease live longer.

C．Some cancers can be cured by aspirin.