He had to drop out of the race because his leg was injured.
因為他的腳受傷了,他不得不退出比賽。
drop out 有退出和退學的意思。
He dropped out of school when he was fifteen.
他15歲時退學了。
如果drop out連成一個單詞,寫成dropout或drop-out,就變成一個名詞,意思是退學生。
His mother doesn't want him to be friends with those dropouts.
他的媽媽不想他和那些退學生交朋友。