A piece of colored paper is 10cm long and 8cm wide. How many circles with a radius of 2cm can you cut at most?

A piece of colored paper is 10cm long and 8cm wide. How many circles with a radius of 2cm can you cut at most?

Four, because the radius is 2cm, the diameter is 4cm, in the limit of width, only two can be cut out, so it takes up 4cm of the length, so the length is still 6cm, so only two can be cut out, so it is four

The radius of the top bottom of a round table is 5cm, the radius of the bottom bottom is 10cm, the length of bus AB is 20cm, where a is on the top surface and B is on the bottom surface. Pull a rope from the middle point m of AB and turn around the side of the round table to point B, then the shortest length of the rope is ()
A. 30cmB. 40cmC. 50cmD. 60cm

Let the shortest distance be MB ', let OA = R, and let the angle of the center be α, then we know from the title that 10 π = α R & nbsp; 1, 20 π = α (20 + R) & nbsp; 2, from the solution of (1) and (2), α = π 2, r = 20, O

A rectangular iron block, 15 cm long, 10 cm wide and 5 cm high, is forged into a cylinder with a bottom of 25 cm to calculate the height of the cylinder
fast

Cuboid volume: 15 * 10 * 5 = 750 cm3
Column height: 750 / 25 = 50cm

100 point system, please analyze

92 .
According to the proportion of 100 points, the full score is 92 points
120 full marks
72 passed
102 points

23. In Mendel's genetic experiment of two teams of relative traits, the one with the ratio of 1:1:1:1 is ()
1. The proportion of F1 producing gamete type 2. The proportion of F2 phenotype 3. The proportion of F1 test cross progeny type 4. The proportion of F1 phenotype 5. The proportion of F2 genotype
A. 2 and 4
B. 1 and 3
C. 4 and 5
D. 2 and 5

BF1: AABB F2: AABB (× 1) AABB (× 2) AABB (× 2) AABB (× 4) AABB (× 1) AABB (× 2) AABB (× 1) AABB (× 2) AABB (× 1) 1: produce gamete AB AB (1:1:1:1) statistical data, so want to be a lot of gamete 2: phenotype 9:3:3:! 3

The characteristic of hemoglobin is ()
A. Easy to combine with oxygen, easy to separate from oxygen B. not easy to combine with oxygen, not easy to separate from oxygen C. easy to combine with oxygen, not easy to separate from oxygen D. not easy to combine with oxygen, easy to separate from oxygen

Blood consists of plasma and blood cells. Blood cells include red blood cells, white blood cells and platelets. The reason why red blood cells are red is because there is a red iron containing protein in red blood cells, called hemoglobin. The characteristics of hemoglobin: in places with high oxygen content, it is easy to combine with oxygen; in places with low oxygen content, it is easy to separate from oxygen. Therefore, it has the function of transporting oxygen So select: a