helicopter的復(fù)數(shù)形式是直接在單詞后加s，第三人稱(chēng)單數(shù)形式是helicopters，過(guò)去式形式是helicoptered，過(guò)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(jī)在村落上空盤(pán)旋數(shù)次才降落。
2、The rescue helicopter made another sweep over the bay.
救援直升機(jī)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(jī)像兩個(gè)小黑點(diǎn)出現(xiàn)在地平線上。
4、Stay well away from the helicopter when its blades start to rotate.
直升機(jī)的螺旋槳開(kāi)始轉(zhuǎn)動(dòng)時(shí)，盡量離遠(yuǎn)點(diǎn)兒。
5、A helicopter was scrambled to help rescue three young climbers.
直升機(jī)接到命令，緊急起飛前去營(yíng)救三個(gè)登山的年輕人。