第1题:
解析：由文中可知，充足和不充足的睡眠周期会导致体重增加、胰岛素敏感性下降，血糖异常，因此D选项正确。
第2题:
解析：它不能重置身体的新陈代谢。最后一句说到“The so-called recovery sleep cannot reset the body's metabolic clock（所谓的恢复性睡眠不能重置身体的新陈代谢时钟）”，因此恢复性睡眠并不能重置身体的新陈代谢。B选项正确。
第3题:
解析：本篇短文说到的睡眠不足和睡眠充足和健康之间的关系，因此C选项正确。
原文：
Few things are more satisfying than sleeping late on weekends. But though the extra sleep may improve your mood, it does not appear to improve your health. Sleep loss can increase our risk of cardiovascular disease, cause weight gain, decrease insulin sensitivity and increase our risk of diabetes.
However, scientists these days are more interested in how this cycle of- -insufficient sleep in weekdays, weekend recovery sleep, and again, insufficient sleep- -can impact your risk of obesity and metabolic disease.
Their findings showed that after the weekend, when people went back to getting insufficient sleep during the work week, their liver and muscle insulin sensitivity, or blood sugar regulation was reduced.
Quite interestingly, these results were not found in people who always maintain insufficient sleep schedules in both weekdays and weekends. The so-called recovery sleep cannot reset the body’s metabolic clock and may actually lead to some serious health issues.
Questions 28 to 30 are based on the passage you’ve just heard.
28. How does the cycle of sufficient and insufficient sleep affect people’s health?
29. According to the speaker, what can be said about recovery sleep?
30. What is this passage mainly about?
