请教问题了

each of the integers from 0 to 9,inclusive,is written on a separate slip of blank paper and the ten slips are dropped into

a hat. if the slips are then drawn one at a time without replacement,how many must be drawn to ensure that  the numbers

on two of the slips drawn will have a sum of 10?

A.Three

B.Four

C.Five

D.Six

E.Seven

这道题的英文我都没怎么看懂，更不要说解题思路了，谁会做教教我

谁会做啊？

10个签，每个签上有个数字，0，1，2，。。。9

问最少抽几个签才能保证有两张的和是10

1+9，2+8，3+7，4+6都等于10，这8个数里至少5张才能保证配上一对，其余的5和0落单

所以要至少7个咯