Saltpeter
n. 硝石, 硝酸钾, 硝酸钠\\n[化] 硝石
✅ 同义词
🗣️ 情景例句
I don't know.
我也说不上来。
He has a writig brush.
他有一支毛笔。
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。