tpo 24 Breathing During Sleep 最后一题多选题有疑问

xianggebenbenUID: 3091234

原题如下：
13.Directions: From the seven statements below, select the statements that correctly characterize breathing during wakefulness and those statements that correctly characterize breathing during sleep. Drag each answer choice you select into the appropriate box of the table. Two of the answer choices will NOT be used. This question is worth 3 points.
A.The role of the rib cage increases and the role of the diaphragm decreases.
B.Carbon dioxide in blood rises and oxygen drops.
C.The coughing reflex is extremely complex.
D.A great deal of effort is used for breathing.
E.Upper airways are resistant to colds and allergies.
F.There is a drop in the volume of air that is exchanged.
G.Automatic and voluntary respiratory systems are both involved.
这道题我只有F选项比较疑惑：答案把它归在sleep的特征里，答案的解释说看第六段第二句
The amount of air exchanged is even lower in REM than NREM because, although breathing is more rapid in REM,it is also more irregular, with brief episodes of shallow breathing or absence of breathing. In addition, breathing during REM depends much more on the action of the diaphragm and much less on rib cage action.
我的理解是REM 和NREM 是指sleep的两个阶段，所以说sleep的时候空气交换量低貌似不对，请指教。

sokillerUID: 3446082

如果我没记错的话，REM和NREM是两种睡觉类型，即浅睡眠和深度睡眠，两者都涉及较低的空气交换量，只不过REM更低些。