Question

Not until he retired from teaching three years ago       having a holiday abroad.

1. A.
   he had considered
2. B.
   had he considered
3. C.
   he considered
4. D.
   did he consider

Answer 1

D
考察倒装句。Not until引导时间状语，放在句首的时候，后面使用部分倒装的形式，排除AC；根据句意本题使用一般过去时，句意：知道三年前他退休，他才考虑出国度假。