新编四级听力练习 第237期

Test 1
Section C
As men age, they (36) ______ get less and less deep sleep--a fact that could be (37) ______ to the weight gain that often middle-age, medical researchers said this week.
The (39) ______ between sleep and "love handles" (俚语，腰部赘肉), double chins and expanding paunch (大肚子) centers on a hormone normally (40) ______ during deep sleep, the scientists from the University of Chicago reported in the August 16 (41) ______ of The Journal of the American Medical Association.
With less deep or slow-wave sleep, there is less bodily production of the growth hormone. That deficiency is (42) ______ with increased fat tissue and abdominal obesity, reduced muscle mass and strength and reduced exercise capacity. These results are particularly noted in the (43) ______ .
The researchers found that deep sleep in men younger than 25 was about 20 percent of a night's sleep. (44) ______________________________________________________ . After age 35, it's 5 percent or less. By the time men reach 45, they have nearly lost the ability to fall into deep sleep and (45) ________________________________ .
The researchers said any treatment to improve a man's sleep would need to begin at age 35-40. A new drug is tested to see if it will increase deep sleep. Methods other than medicine can boost deep sleep--for example, increasing body heat by taking a hot bath before bed. (46) ________________________________________ .