What surprised me was(that he spoke English)so well.

What surprised me was(that he spoke English)so well.
用that是因为它是同位语从句么?
There is no indication(that)the talks have been successful.
这里也是同位语么?
You may rely on it(that)everything will be ready by Monday.
这里that 也是同位语?
The question is ____to land men there.
A.Whether it was safe B.Whether safe it was
为什么选A不选B?
Why___at a given time is not known.
A.a drought should occurB.a drought that occurs
为什么选A不选B?怎么翻译?