【多选题】下列n(n > 2)阶行列式的值必为零的是( )A.行列式中非零元素的个数小于n; B.行列式中有一半的元素等于零;C.行列式主对角线上的元素全为零; D.行列式的元素中每个数都重复出现n次.
【单选题】What will be the main purpose of the show?
A.
To demonstrate the latest use of computer graphics.
B.
To raise funds for public television programming.
C.
To explain the workings of the brain.
D.
To increase membership in professional medical societies.
【单选题】在计算实心砖墙时,应扣除单个面积在( )以上的空洞所占的体积。
【单选题】一个n阶行列式的非零元素少于n个,则该行列式的值为