以f或者fe结尾的单词变为复数时要把f或者fe改为v再加上es,比如：knife-knives、wife--wives
相关介绍
Two knife racks hold her favourite knives.
两个刀架上存放着她最心爱的刀具。
Put the knives in the kitchen drawer
把这些刀具放到厨房抽屉里。
Many wives felt tied to housework.
很多妻子觉得自己被家务束缚住了。
Their wives are sisters.; They are in-laws.
他们是连襟。
