正确答案为选项D，在录音中的相关信息为Lack of deep sleep incurs serious health problems, such as…"，关键词 obesity (肥胖）与 gaining too much weight 意思相同。选项A 所给的意思是缺乏睡眠导致脑神经细胞之间形成更多联系，而录音内容提到神经细胞之间更多联系是说睡眠的正面作用，而不是说缺乏睡眠的坏处。录音中说深度睡眠是记忆形成所必需的，而非问题中的缺乏睡眠，B 项显然错误。选项 C 也是犯了同样的方向性错误。

[重点难点]
准确抓住并识别obesity与 gaining too much weight之间的关联意义。

[录音原文]
Researchers find that sleeping forms significantly more new connections between neurons. Deep sleep was necessary for memory formation. During this stage, the brain was “replaying” the activity from earlier in the day. Lack of deep sleep incurs serious health problems, such as cancer, heart disease, type-2 diabetes, infections, and obesity.