i don't know whether you have received my last letter or not.
我不知道你是否已收到我上一封信。
lat.est
adj.(形容词)Superlative of late late的最高级形式n.(名词)Something that is the most recent or current of its kind:最近的:最新的或新潮的事物:例句:the latest in electronic gadgetry.最新的电器发明
<习惯用语>at the latest
No later than:最迟:例句:Have it done by Tuesday at the latest.最迟得在星期二完成
习惯用语>