常見例句Her letter were writeen in a happy strain. 她的信是用快樂的筆調寫的。The union of A and B, writeen as AUB, is the set of elements which belong to A or B or to both. A與B的并集記為AUB，是屬于A或屬于B，或同時屬于兩者的元素的集合。 返回 writeenable