Fcv
abbr. fill-and-check valve 注入与检查阀门
🗣️ 情景例句
Why is that necessary?
为什么有此必要
People go to visit their parents, relatives and friends.
人们出门探望父母、亲威和朋友。
When you visit London, one of the first things you will see is Big Ben,
当你游览伦敦时，首先看到的东西之一就是“大本”钟，