People in the west make_____a rule to buy Christmas presents for their relatives and friends.
When exposed to stress, in ________ form, all of us react both chemically and physically.
After he was promoted to the present position, he is not so hardworking as he ______.
What actually ______ the accident has not yet been determined.
-- What were you up to when she dropped in? -- I _____ for a while and _____ some reading.
The Education Department says that school safety has set off alarm bells with frequent reports of serious accidents______ students got injured or killed.