（辨认主题句）Choose the best topic sentence from the four options below.Write the corresponding letter of your choice in the blank provided.

Your choice:

（辨认主题句）Choose the best topic sentence from the four options below.Write the corresponding letter of your choice in the blank provided.

Your choice:

A.Passive smokers may easily catch the diseases active smokers invite.

B.Passive smoking is becoming widely recognized as a major health hazard.

C.Researchers find that second-hand smoke increases one’s risk of lung cancer.

E.Passive smoking refers to the second-hand smoke that nonsmokers breathe in.

正确答案是B