Flsorescence
[医] 萤光, 荧光
🗣️ 情景例句
He ventured his life to rescue a drowning child.
他冒着生命危险去抢救一个溺水的孩子。
Easier said than done.
说话容易做事难。
What happened before printing was invented?
印刷术发明以前是怎么一回事？