Commutative operation
[計] 可交換操作
?? 詞語組成解析
a. 交替的, 交換的\\n[法] 交換的, 代替的, 互相的
operation
[,ɑp?'re??n]
n. 操作，經(jīng)營;手術(shù);[數(shù)]運算;作用;
oper 工作 + ation 表示行為、狀態(tài)、過程 → n.操作；手術(shù)；運算
??? 情景例句
I waited for you for about a quarter of an hour.
我等了你差不多一刻鐘。
Then the damage must be caused at somewhere along the line where the goods weren't handled properly.
那么殘損一定是在運輸途中的什么地方對貨物處理不妥造成的。
You have my word!
我保證！