问题
选择题
Not until he retired from teaching three years ago having a holiday abroad.
A． he had considered
B． had he considered
C． he considered
D． did he consider
答案
答案：D
Not until位于句首时句子要倒装，consider having a holiday abroad这个动作发生在retire之后，所以用一般过去时。
【考点】特殊句式—倒装。