cxd-65页85

if s is an infinite set of real numbers, is there a number in s that is less than every other number in s?

(1) Every number in S is an interger.

(2) Every nubmer in S is positive.

答案是C. 但是如果S中有重复的数字,如{1,1,1,2,3...},那就没有,如果{1,2,3,,,,},那就是有,还是不确定啊