问题补充：
I get the two of them mixed up; they are so similar.
A. at one time
B. at no time
C. in no time
D. all the time
答案：
A. at one time
B. at no time
C. in no time
(答案→)D. all the time
解析：考查介词短语。at one time以前，曾经；at no time绝不；in no time立刻，马上；all the time一直；句意：我一直搞不清楚他们俩，他们是如此的类似。
