单选题 The purpose of the chart is to show______.

A、 the percentages of smokers in schools
B、 the increase of smokers in grades 9—12 during 2005—2009
C、 the number of teenage smokers in grades 9—12
D、 the amount of money spent by young smokers over the years

【正确答案】 B

【答案解析】

单选题 Which grade had the highest percentage of smokers in 2005?

A、 The 9th.
B、 The 10th.
C、 The 11th.
D、 The 12th.

【正确答案】 C

【答案解析】

单选题 The percentage of the 9th grade smokers in 2009 was______.

A、 23.2
B、 25.2
C、 31.2
D、 33.4

【正确答案】 D

【答案解析】

单选题 Which grade saw the greatest increase of smokers over the four years?

A、 The 9th.
B、 The 10th.
C、 The 11th.
D、 The 12th.

【正确答案】 A

【答案解析】

单选题 What tendency can we find from the chart?

A、 Smokers in all grades have increased.
B、 The higher the grade, the more the smokers.
C、 The older a student, the more he smokes.
D、 Low graders smoke less heavily.

【正确答案】 A

【答案解析】