R.s.p.
[医] 右骶后(胎位)
🗣️ 情景例句
Study hard and study everyday, if you want to master the English language.
如果你想精通英语的话，就得每天刻苦学习。
Do you have a book?
你有一本书吗？
So the number of stars that we know exist is now estimated at about 300 million million million.
因此，我们所知道的现有恒星数目估计约有30亿×1000亿颗。