19At that time, people_____early in the morning in winter, and coal them warm

I met my teacher _____ I was walking in the street, but I didn’t say hello to him.

____ visited the Shanghai World Expo is sure to tell you the place is worthy ____ twice． — You can say that again．

I soon found that the work I was doing had already been done by someone else－, I was wasting my time.

_______ interests me most in the world isthe natural beauty of Guilin.