Sterad
球面(角)度, 立体角度的单位
🗣️ 情景例句
Never know what?
说不定什么？
This is the book that I promised to lend you.
这就是我答应借给你的那本书。
Later a neighbour told me about him.
后来，一位邻居告诉了我他的情况。