参考答案：C

解析：[听力原文]It is estimated that over 400,000 Americans every year die of smoking related diseases. But kicking the habit is not so easy. A new study finds that smokers who smoke menthol cigarettes could have more trouble trying to quit compared to people who use non-menthol cigarettes. When a study began in 1985, 1,500 smokers had a medical exam and answered the questions about their smoking habits. 63% of the smokers said they preferred menthol cigarettes, and these smokers who preferred menthols were less likely to have quit smoking after 15 years. 69% of the menthol smokers were still smoking when researchers asked again about smoking habits in the year 2000. Among people who had originally preferred non-menthol cigarettes, 54% were still smoking in 2000. The researchers say that both menthol and non-menthol cigarettes are equally dangerous, but menthol cigarettes may actually be harder to quit.[难点] 此题比较容易。