When we sleep is cultural as biological-and practices differ greatly round the globe.
A. that much
B. so much
C. too much
D. as much
网友回答
A. that much
B. so much
C. too much
(答案→)D. as much
解析：考查同级比较：as +adj+as结构，as much as和…一样多，句意：我们什么时候睡觉在文化上和生理上一样多，做法全世界都不同。选D。