When did you leave the office yesterday afternoon—____ I finished my work.

Does your brother get up early or late—He used to _________very late， but now he is used to _________ early.

I believe that the 21st century is one ______ China will become one of the most powerful economic countries.

Smoking ______ in the kitchen in my house.

The children all looked_______ at the brokenmodel plane and felt quite_______.