纠正措施应与已发生不符合的影响相适应。()
参考答案:对
将自然数1,2,3,…,21这21个数,任意地放在一个圆周上,证明:一定有相邻的三个数,它们的和不小于33.
Suan , you are so lazy.This job ___ hours before.
A.should finish
B.could be finished
C.must have been finished
D.should have been finished