1basic course
2basketball game
3bathing suit
4be a mystery to someone
5be/feel under the weather
6be/run low
7be about to
8be absent from school
9be absorbed in
10be accustomed to
11be acquainted with
12be addicted to
1be all in a day's work
2be allergic to sth.
3be amazed at
4be attached to
5be backed up
6be behind the time
7be behind schedule
8be better off
9be booked up
10be bound for
11be bound to
12be burned up