M: Of course you can. Every one has his personal matters to deal with more or less, but don't chat over the phone.

m：当然可以，每个人都多多少少有私事要处理，但是别用电话聊天。

youdao

M is called taxonomic class of sets if. for every two elements of m, either they are disjoint, or one is a subset of the other.

若m中任意两个子集，或者它们无共同元素，或者一个是另一个的子集，这样的M称为分类集。

youdao

M is called taxonomic class of sets if. for every two elements of m, either they are disjoint, or one is a subset of the other.

若m中任意两个子集，或者它们无共同元素，或者一个是另一个的子集，这样的M称为分类集。

youdao