几道英语根据所给汉语完成句子的题目（初二哒~）…………

几道英语根据所给汉语完成句子的题目（初二哒~）…………
Terrorists _________（引起了） many tragedies.
Our English class often _________（结束） up with a song.
Before you _________（跨过） the street,you must look both ways.