题目内容:
Whichofthefollowingtellsushowcaffeineaffectssleep?
A.Itblocksproductionoftheenzymethatstopsmelatoninproduction. B.Itinterruptstheflowofthehormonethatpreventspeoplefromsleeping.
C.Ithalvesthebody'slevelsofsleephormone.
D.Itstaysinthebodyformanyhours.
参考答案:
答案解析: