一道sat语法IS题.When in 1833 a london carpenter designed the first prefabricated house,( making certain that a single person can) carry any of the precut panels from which it was assembled.A>making certain that a single person canB>making certain that a single person couldC>He makes certain that a signle person cand>he made certain that a single person coulde>he has made certain that a single person could为什么不是b而是d?
问题描述：
一道sat语法IS题.
When in 1833 a london carpenter designed the first prefabricated house,( making certain that a single person can) carry any of the precut panels from which it was assembled.
A>making certain that a single person can
B>making certain that a single person could
C>He makes certain that a signle person can
d>he made certain that a single person could
e>he has made certain that a single person could
为什么不是b而是d?
答