I saw him _____ behind the tree, thinking.
The ability ________ an idea is as important as the idea itself.
We were just about ready to leave _____ it started to snow.
It’s a mistake to think of Chongqing only ______ its tourist attractions.
Is this the young engineer ________ you want to have ________ the computer for me?
-----They used to be good friends, but now they are like strangers. ----- How _____ this ______?