求教 数学讨论稿14题

非同反想

14.    m,n is opposite from z on the line, m>n?
1) distance between m and zero is three time larger than distance between n and zero
2) sum of m and n >0
I不充分，m和n的正负不知道
II m+n>0,不能确定m和n的正负，不充分
I+II，充分，m>0>n，选C
m,n is opposite from z on the line这句话什么意思？
谢谢

非同反想

哦 谢谢。。