helicopter的復(fù)數(shù)形式是直接在單詞后加s，第三人稱單數(shù)形式是helicopters，過去式形式是helicoptered，過去分詞形式helicoptered，現(xiàn)在分詞形式helicoptering。
例句：
1、The helicopter made several passes over the village before landing.
直升機在村落上空盤旋數(shù)次才降落。
2、The rescue helicopter made another sweep over the bay.
救援直升機在海灣上空又搜索了一遍。
3、The helicopters appeared as two black dots on the horizon.
直升機像兩個小黑點出現(xiàn)在地平線上。
4、Stay well away from the helicopter when its blades start to rotate.
直升機的螺旋槳開始轉(zhuǎn)動時，盡量離遠點兒。
5、A helicopter was scrambled to help rescue three young climbers.
直升機接到命令，緊急起飛前去營救三個登山的年輕人。