Upconversion
上变频; 上转换; 升频转换
🗣️ 情景例句
How soon will my mail be received by the other end?
我的信件多快能被对方收到？
Don't forget to write to me.
不要忘记写信给我。
Most children have such a high ideal of their parents,
大多数孩子对父母估价过高，