”Social basic contradiction is the basic motive force of social development

”Social basic contradiction is the basic motive force of social development

Social existence determines social consciousness, and social consciousness reacts on social existence

Is my favorite plural or singular
If xxxxx is a subject, is it singular or plural?

Be verbs in subjects
my favorite subject is maths
My favorite are in the plural

How to calculate the surface area of a cylinder with a radius of 5cm and a height of 12cm?
Formula!

2×5^2×3.14+2×5×3.14×12

15 and 45, 16 and 72, 1 and 8, 33 and 22, 8 and 9, 3 and 15

. greatest common factor. Least common multiple
15 and 45.15.45
16 and 72.8.144
1 and 8.1.8
33 and 22.11.66
72 8 and 9
3 and 15

In the triangle ABC, ab = 7, BC ∶ AC = 4 ∶ 3, find the perimeter range of the triangle ABC, please explain in detail

Let AC = 3x
There is x1
The perimeter is 7x + 7 and the range is 14 to 56

If we know that the greatest common factor of two numbers is 6 and the least common multiple is 36, and we know that one of them is 12, then the other is 12______ ．

Because 36 △ 6 = 6, 6 = 1 × 6 = 2 × 3, there are two cases of these two numbers: 6 × 1 = 6, 6 × 6 = 36 or 6 × 2 = 12, 6 × 3 = 18, so one of them is 12, then the other is 18

In Excel, A1, B1, C1, A2, B2, C2 are integers of 0-9. Take the value of B1 and compare it with A2, B2, C2. Write the comparison result into D2
When the value of B1 is 0, and the value of any cell of A2, B2, C2 is equal to 0, the value of D2 is wrong, otherwise it is right
When the value of B1 is: 1, and the value of any cell of A2, B2, C2 is equal to 8, the value of D2 is: wrong, otherwise: right
When the value of B1 is: 2 and the value of any cell of A2, B2, C2 is equal to 6, the value of D2 is: wrong, otherwise: right
When the value of B1 is: 3 and the value of any cell of A2, B2, C2 is equal to 4, the value of D2 is: wrong, otherwise: right
When the value of B1 is: 4, when the value of any cell of A2, B2, C2 is equal to 7, the value of D2 is: wrong, otherwise it is: right; when the value of B1 is: 5, when the value of any cell of A2, B2, C2 is equal to 9, the value of D2 is: wrong, otherwise it is: right
When the value of B1 is: 6, and the value of any cell of A2, B2, C2 is equal to 1, the value of D2 is: wrong, otherwise: right
When the value of B1 is: 7, and the value of any cell of A2, B2, C2 is equal to 2, the value of D2 is: wrong, otherwise: right
When the value of B1 is 8, when the value of any cell of A2, B2, C2 is 4, the value of D2 is wrong, otherwise it is right. When the value of B1 is 9, when the value of any cell of A2, B2, C2 is 6, the value of D2 is wrong, otherwise it is right
How to achieve
If you feel that there is anything unclear, you can directly: Hi me, please don't answer casually

In order to make the formula short, we select A2: C2, and then click the name box to define the name as a. write the formula in D2: = if (choose (B1 + 1, countif (a, 0), countif (a, 8), countif (a, 6), countif (a, 4), countif (a, 7), countif (a, 9), countif (a, 1), countif (a, 2), countif (a, 2), countif (a, 6), countif (a, 4), countif (a, 7), countif (a, 9), countif (a, 1), countif (a, 2), Counti

My favorite fruit is grape
Is grape singular or plural

Grapes are my favourite fruit
You can't just like one grape, can you?!

As shown in the figure, it is known that the parabola y = AX2 + BX + C intersects the X axis at two points a and B, intersects the Y axis at point C, D is the midpoint of OC, and the straight line ad intersects the parabola at point E (2,6), and the area ratio of △ Abe and △ ABC is 3:2 (1) Find the function relation of this parabola; (2) connect BD, try to judge the position relation between BD and ad, and explain the reason; (3) connect BC intersection line ad to point m, on the line ad, whether there is such a point n (not coincident with point m), so that the triangle with a, B, n as the vertex is similar to △ ABM? If it exists, request the coordinates of point n; if not, please explain the reason

(1) According to the area ratio of △ Abe to △ ABC is 3:2 and E (2,6), we can get C (0,4).. D (0,2). From D (0,2) and E (2,6), we can get the function relation of the straight line ad as y = 2x + 2. When y = 0, 2x + 2 = 0, we can get x = - 1.. a (- 1,0). From a (- 1,0), C (0,4) and E (2,6), we can get the function relation of the parabola as y = - x2 + 3x + 4 (2) BD ⊥ ad. (3) method 1: m (23103), am = 535. From △ anb ⊥ ABM, ANAB = ABAM, that is AB2 = am · an,  52 = 535 · an, the solution is an = 35. Thus n (2,6) can be obtained. Method 2: from ob = OC = 4 and ⊥ BOC = 90 °, ANAB = 45. From BD ⊥ AD and BD = de = 25, ⊥ AEB = 45 ° . AEB ∽ ABM, i.e. point e satisfies the condition, n (2,6)

What is A-B = 3, B-C = - 2A + B + c-ab-bc-ca

Original formula = 1 / 2 [(a-b) ^ 2 + (A-C) ^ 2 + (B-C) ^ 2]
Because A-B = 3, B-C = - 2
So a-c = 1
So the original formula = 1 / 2 * (9 + 4 + 1) = 7