You should sleep_______nine hours every nighta.in b.with c.at d.for

问题描述:

You should sleep_______nine hours every night
a.in b.with c.at d.for

d for后面加时间

d

d.for

睡九个小时 D

D是表示一段时间
in nine hours 是九个小时内所以A不对

D