Photicity
光化率
🗣️ 情景例句
Put my experience on the line ...
考验考验我的阅历……。
That's unbelievable.
那是难以置信的。
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。