问题补充：
John passed the examination though he had only spent on the subject as others had done.
A. as half time much
B. as half much time
C. half as time much
D. half as much time
答案：
A. as half time much
B. as half much time
C. half as time much
(答案→)D. half as much time
解析：考查倍数问题。as...as 结构，此句型意为“…和…一样…”。中间可加形容词、副词、可数不可数名词，本题中time是不可数名词，结构为as much/little＋<不可数名词>＋as，因此half不能出现在as...as中间
