Question 24 is based on the passage you have just heard.

Passage Three

听力原文

    In a recent study carried out by psychologists on the disruptive effects of smartphones, (22) [two groups of college students were given word search puzzles.] The first group was told to complete the puzzles with its participants’ smartphones in their line of sight. The second group, however, was told that the phones would interfere with equipment in the experiment and would need to be moved away from the testing area. Midway through the second groups solving of the puzzles, the experimenter called one of the phones, and let it ring for a while before hanging up. (23) [Many of the students in that group were unable to focus from then on, becoming anxious and performing more poorly than the first group.] 

    Use of electronics has also been known to lead to a decline in human interactions. Rather than having real-life conversations, many express emotions and engage in deep conversations through social media sites. Many students use their phones and computers during class for non-academic activities, which leads to poor grades. (24) [Perhaps the most dramatic impact is the reduction in the amount of sleep, which leads to poor health and weight gain.]

    (25) [Technology is a great tool. However, it’s important to recognize its downsides.] Lack of sleep, reduction of productivity and weight gain are only a few. If we are not careful about all these minor problems right now, the effect on the future generation is going to be much bigger.

24. According to the passage, what is the most dramatic impact of smartphone use?

解析：D。录音后半部分提到，也许使用智能手机带来的最大影响是睡眠时间的减少，D项在录音中原词复现，符合录音中的意思，故D项正确。

错项排除：A项利用录音中出现的activities和reduction的近义词decline进行细节拼凑，录音结尾提到体重增加是负面影响之一，但并没有说与体育运动有直接关系，故排除。录音中说到睡眠减少会导致体重增加，但在录音中未提及情绪问题会增加，故B项可排除。录音中提到了poor grades，但这并不是最大的影响，故C项可排除。