Subadditivity
子[次]可加性
🗣️ 情景例句
Would you call Priscilla Smith at FAO Schwarz, please?
请拨电话给FAO Schwarz的Priscilla Smith ，好吗？
People go to visit their parents, relatives and friends.
人们出门探望父母、亲威和朋友。
How kind! You were lucky.
她多好啊！你很幸运。