lifesaver的复数形式怎么写？

lifesaver的音标：lifesaver的英式发音音标为：['laɪfseɪvə(r)]lifesaver的美式发音音标为：['laɪfˌsevɚ]...

The cervical smear test is a lifesaver.宫颈涂片检查能够帮上大忙。The new drug is a potential lifesaver.这种新药有可能成为一种救命药。He thought of the old man as his lifesaver.他把老人看作他的救命恩人。...

n.救生者，水难救生员，济急的人...