Fill in the following numbers in the corresponding set -(+ 7) - three and half 6.5 + 0.40.2 - (- 3) five thirds 0 + (- 5) - twenty two seventh Set of positive numbers: Score collection: Set of integers: Set of negative numbers: Set of nonnegative numbers: Set of rational numbers:

Fill in the following numbers in the corresponding set -(+ 7) - three and half 6.5 + 0.40.2 - (- 3) five thirds 0 + (- 5) - twenty two seventh Set of positive numbers: Score collection: Set of integers: Set of negative numbers: Set of nonnegative numbers: Set of rational numbers:

See if it's like this:
Positive numbers: 6.5, + 0.4, 0.2, - 3, 5 / 3
Scores: - 1 / 3, + 0.4, 0.2, 5 / 3, - 22 / 7
Integers: - (+ 7), + (- 5), 0
Negative numbers: (+ 7), - three and a half, + (- 5), - 22 / 7
Nonnegative: positive plus 0
Rational numbers: all
I don't know. Are you satisfied?

If each student has to vote and can only vote for two candidates, to ensure that two or more students must vote for the same two candidates, then the students in this class should have at least ()
A. 10 people B. 11 people C. 45 people D. 46 people

∵ there are c210 = 10 × 92 = 45 combinations of 10 people who can choose 2 people at random ∵ if there are 45 people who participate in the voting, it is impossible to guarantee that there will be 2 people because the above 45 kinds of voting results may happen. ∵ in order to ensure that there will be 2 people voting the same vote ∵ at least 45 + 1 = 46 people, so choose D

As shown in the table below, the numbers in the table are arranged according to certain rules. Guess: the number in the fifth row and fifth column is______ The number of n-th row and n-th column is______ ． 1 2 5 10 4 3 6 11 9 8 7 12 16 15 14 13

∵ the number in the first column of the first row is 1, the number in the second column of the second row is 3 = 2 × (2-1) + 1, the number in the third column of the third row is 7 = 3 × (3-1) + 1, the number in the fifth column of the fifth row is 5 (5-1) + 1 = 21, and the number in the nth column of the nth row is n (n-1) + 1 = n2-n + 1