Since entry into high school the students have been ________ staying up late in the evening and getting up early in the morning.

I saw Helen in the school just now.— It ______ be Helen. She has gone to the shopping center with her sister.

The customers are pleased with the_______ of the restaurant.

Whenever I met her，________ was fairly often，she greeted me with a sweet smile.

How_______ is the subway station—About three miles___________ .