-Who’s that man riding along the street. Is it Tom?-It ______ be Tom. I saw him in the library just now.
一How do they get to school? 一They ________ the subway.
Mr. Zhang ________ to school on the school bus every day.
It takes rile an hour ______ to school by bike.
一What’s the matter _____ her? 一She has a toothache.