答案:B
下列表现为虚劳的特点的有()
A.神疲乏力
B.倦怠
C.形羸面黄
D.舌嫩脉弱
E.潮热盗汗
The boy was so tired that he fell asleep _______ his mother could take off his clothes.
A.before
B.after
C.while
D.when