健康的生活方式提倡每天保持多少小时睡眠（）。
A.3～4小时
B.4～5小时
C.5～6小时
D.7～8小时
E.8～9小时
参考答案：D
. Some inventions are well received, but _____ function, they aren't very successful.
A. according to B. in terms of C regardless of D. owing to
螺旋缠丝劲之一的病手“缺陷”是怎么回事？
