Keratan
角质素
🗣️ 情景例句
My name is Richard Stewart.
我的名字是Richard Stewart。
I hope you change his decision.
我希望你改变他的决定。
The cry had certainly come form one of the chimneys, but as there were so many of them, the fire fighters could not be certain which one it was.
喊叫声肯定是从烟囱里传出来的，然而，因为烟囱太多，消防队员无法确定到底是哪一个。