______________ about wild plants that they decided to make a trip to Madagascar for further research.

Every evening after dinner, if not       from work, I will spend some time walking my dog.

Across North China      in the world, namely the Great Wall.

Under no circumstances _______ the difficulties when they were on an expedition to the Antarctic．

Only when he returned______ the truth.

In the south of the city ______ two railway lines.

— Did you know any French before you arrived in Washington?
— Never ____ it, actually.

So much of interest _______ that most visitors simply run out of time before seeing it all.

We arrived at a farmhouse, in front of ______.

Wang Lin failed to be admitted by Hong Kong University last year, and only then _______ the importance of English.