Rule: Six patterns are divided into three groups, the second of each group is a subset of the lines of the previous pattern, and the subset pattern retains the elements of large vertex angle and left and right mirror images. For example, mode 2 is a subset of mode 1 and mode 4 is a subset of mode 3. Only answer b conforms to the law of this subset.

2. answer D.

Rule: Count the number of black parts in each pattern, which are 1, 4, 3, 2, then? The number should be 5. Answer d matches.

3. answer D.

Rule: All three-dimensional figures, excluding B and C, in the legend, there are four points on one side of the three-dimensional figure, 1 point and three points, and there are figures with two points on one side, only the answer D meets.

4. answer D.

Rule: The sum of all sides in each group of three patterns is the same. The total number of edges of the three patterns in the first group is 14, while the total number of edges of the first two patterns in the second group is 12, and only D meets the answer.

19, answer D.

Calculation: There are many people in the department, so the payment is more. Compare the payment differences between different departments:

175- 105=70

3 15-280=35

3 15- 175= 140

280- 175= 105

It can be seen that the price difference between the sales department and the product R&D department is the smallest, and the payment price difference is 35 yuan. Assuming that 35 yuan is the contribution of K people, the total contribution is 875 yuan, and the total number of people =875/35*k=25k.

The answer is only that D is divisible by 25 (K= 1 hour), so there are 25 people in a * * *, and each person pays 35 yuan.

20. a.

Calculation: If you calculate the minimum prize of the first prize, you need to maximize the prizes of other prizes.

To maximize the remaining bonus, there should be a minimum incentive bonus to maximize the difference with the second, third and fourth prizes, that is, 654.38+00000 yuan to ensure that the second, third and fourth prizes are also maximized.

Let the bonus be x, y, z, m and n yuan in turn. According to the meaning of the question:

x=n+4

y=n+3

z=n+2

m=n+ 1

Then it is 31= 4n+1+2+3+4+n = 5n+10.

5n=2 1

Then n can get 40 thousand yuan at most Then the fourth, third and second prizes can be 50,000, 60,000 and 70,000 at a time. The remaining 90 thousand yuan.

That is to say, the first prize can get at least 90 thousand yuan.