问题
单项选择题
A．A balance in cognitive thoughts and emotions.
B．A chronic sleep deprivation.
C．A huge wave of sleepiness.
D．A mighty sleep hormone.
答案
参考答案：D
解析：[听力原文]
What is melatonin
搜题请搜索小程序“爱下问搜题”
A．A balance in cognitive thoughts and emotions.
B．A chronic sleep deprivation.
C．A huge wave of sleepiness.
D．A mighty sleep hormone.
参考答案：D
解析：[听力原文]
What is melatonin