题目内容

()是不含任何元素的集合

查看答案
更多问题

空集是()任何元素的集合

一个点可以变为一个集合

A. 对
B. 错

What the man said to the police officer ________by several other witnesses standing by.

A. was disputed
B. were disputed
C. disputed
D. be disputed

答案查题题库