Question

I didn't manage to do it ___you had explained how

I didn't manage to do it ___you had explained how. A.until B.unless C.when D.before 这种题目是看意思做的还是？我为什么觉得ABD都可以

Answer 1

I
didn't
manage
to
do
it
____
you
had
explained
how.
这句话的意思是：直到你解释了如何做，我才做到。
这里应该是考not...
until（直到...才）的用法。答案应该是A
如果选D
before如果后接从句，动词应该是过去式，因为before后面的动作应该是瞬间动作不能延续。此句里you
had
explained
how用的是过去完成时，是延续的一种状态。因此不对
unless
是连词
意思是
除非
它实际上是连接一个条件句。
其用法和
if
是一样的。用在一般时态中。