Retainers
n. （尤指服务多年的）仆人( retainer的复数形式 ); （为保留租房而付的）租房订金; （聘请律师等的）预付费用; 牙齿固位体
🗣️ 情景例句
how would you do it?
你怎么说？
My mother mailed me a parcel.
我妈给我寄了一个包裹。
It has been found that certain bats emit squeaks and by receiving the echoes,
人们发现，某些蝙蝠能发出尖叫声，