Quadrivalency
n. 四价
🗣️ 情景例句
What are you majoring in?
你主修什么专业？
He who wants a mule without fault, must walk on foot.
如要骡子无缺点，只有自己徒步行。
My holidays passed quickly, but I did not send cards to my friends.
假期过得真快，可我还没有给我的朋友们寄过一张明信片。