Elementary school questions, come and answer 10

1. There are about 30,000 species of higher plants.

There are more than 8,000 kinds of woody plants in China, including more than 2,800 kinds of arbor species. There are more than 2,100 kinds of perching ridge propulsions, including more than 450 species of mammals, more than 1,180 species of birds, more than 320 species of reptiles, and more than 210 species of amphibians.

Many species of mammals and more than 130 species of birds have disappeared from the face of the earth. Currently, there are 25,000 species of plants and more than 1,000 species of vertebrates worldwide, which are also in danger of extinction.

Supplement: China is one of the most species-rich countries in the world. China has more than 32,000 species of higher plants, second only to Brazil and Colombia, the world's most abundant higher plants, accounting for the third place in the world

There are 2,200 species of bryophytes, accounting for the total number of species in the world, belonging to 106 families, accounting for 70% of the world's families; There are 52 families of ferns, with about 2,200 and 2,600 species, accounting for 80% of the world's families and 22% of the world's species, respectively. There are 15 families, 79 genera, and about 850 species of gymnosperms in the world, and China has 10 families, 34 genera, and about 250 species, which is the country with the most gymnosperms in the world; There are about 328 families, 3,123 genera and more than 30,000 species of angiosperms, accounting for 75%, 30% and 10% of the world's families, genera and species, respectively. There are more than 7,000 species of woody plants, 1,800 species of terrestrial vertebrates (300 species of reptiles, 1,100 species of birds, 400 species of mammals, accounting for 10% of the world's terrestrial vertebrates, 600 species of freshwater fish, 1,500 species of marine fish, accounting for 10% of the world's fish, and special.

China is one of the most species-rich countries in the world. China has more than 32,000 species of higher plants, second only to Brazil and Colombia, which have the most abundant higher plants in the world, accounting for the third place in the world: 2,200 species of bryophytes, accounting for the total number of species in the world, belonging to 106 families, accounting for 70% of the world's families; There are 52 families of ferns, with about 2,200 and 2,600 species, accounting for 80% of the world's families and 22% of the world's species, respectively. There are 15 families, 79 genera, and about 850 species of gymnosperms in the world, and China has 10 families, 34 genera, and about 250 species, which is the country with the most gymnosperms in the world; There are about 328 families, 3,123 genera and more than 30,000 species of angiosperms, accounting for 75%, 30% and 10% of the world's families, genera and species, respectively.

There are more than 7,000 species of woody plants, 1,800 species of terrestrial vertebrates (300 species of reptiles, 1,100 species of birds, 400 species of mammals, accounting for 10% of the world's terrestrial vertebrates, 600 species of freshwater fish, 1,500 species of marine fish, accounting for 10% of the world's fish, and endemic rare animals and plants: pandas, golden monkeys, ginkgo biloba, and dove trees.

You don't know the questions of elementary school, it's really !!

Summary. Hello, option B for question 4. Cuboids and cubes with equal base circumferences have a larger volume than a cube if they are also of the same height.

Elementary school topics. Help me look at question 4.

Hello, option B for question 4. If the height of the cube and the cube is the same, they are larger than the cube.

The calculation process is as follows: if the bottom circumference is equal to the cuboid and the cube, if their let is also equal to the height of the cube = the base area The height is equal, then whoever has the larger base area will have a larger volume In the case of equal circumference, the area of the square is greater than the area of the rectangle. So the volume of the positive hail seepage cube is greater than the volume of the cuboid.

There are similar topics to help me draw a few inferences.

This to the question also helps me to draw inferences, thank you, together 2 to the question <>

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Extended information: This question is mainly to investigate the volume of the cuboid and calculate the formula: the volume of the rectangular royal finger bridge = length, width and height similar to the volume calculation of the cube and:

The formula for calculating the volume of the cube is: the volume of the cube = the volume of the side length of the ball = 4 3 r The volume of the cylinder = r Teasing h

For example, if there is a fence and you want to enclose a vegetable field, is it a large area to enclose a square vegetable field or a large area to enclose a rectangular sleepy jujube dan.

Set up a total of x pieces of goods, and the total cost is Y yuan.

Equations can be listed:

15x-y=100

8x+40=y

Solving the equation yields: x=20 y=200

So the total cost of these goods is $200.

Solution: There are x products, and the total cost is y yuan.

15x-y=100 (1) ;8x-y=-40 (2)

From (1) we get y=15x-100, then (2) can be reduced to: 8x-(15x-100)=-40 and x=20, then y=200

So the total cost of these goods is $200.

1 180 * 3 (1+2+3) = 180 * 3 6 = 90 right triangles.

2 720 * 3 (3+2) = 200 * 3 5 = 120 km hours.

720 * 2 (3+2) = 200 * 2 5 = 80 kmh.

Distance divided by time = speed and then prorated speed.

1.180 (1+2+3)=30 30*3=90 The maximum angle is 90 degrees, and the right angle is triangular.

2.720 That's two cars at speed and.

200/（3+2）=40km/h

A speed 40*3=120km h

B speed 40*2=80km h

1: The law of the inner angles of the triangle is the sum of the triangles = 180 degrees. Then 180 (1+2+3)=30 degrees;

1 angle is 30 degrees, the second angle is 30 2 = 60 degrees, and the third angle is 30 3 = 90 degrees; So you know.

It is 1 right triangle.

2: Bus speed: 720 km/h;

Truck speed: 720 km/h.

1.Maximum angle: 90 degrees right triangle.

2.Suppose the speed of the passenger car is x km h and the truck is km h2 3x) =720

x = 120

Wagon speed: 2 3x = 2 3*120 = 80 so the speed of the passenger car is 120 km h and the speed of the lorry is 80 km h

Question 1. x+2x+3x=180

x = 30 maximum angle = 3x = 90 degrees, right triangle.

Question 2. 3x+2x)*

x = 40 passenger cars 120, trucks 40

1 The largest is 90 degrees, right triangle.

2 720 This is two cars and speeds.

200/（3+2）=40km/h

A speed 40*3=120km h

B speed 40*2=80km h

The maximum angle is ninety degrees and the right triangle is right.

If the speed of the passenger car is x kilometers per hour, the truck will be 2 3x kilometers per hour.

The solution is x=120

2x/3=80

A: 120 km/h for buses and 80 km/h for cars.

Hello ha! o(∩_o

Solution: Good sentence Li Dong: Wang Qiang: 10,000 yuan).

4 (10,000 yuan) Answer: Li Dong should get a profit of 40,000 yuan, and Wang Qiang should get a profit of 10,000 yuan. Destroy socks answered.

Li Dong 40,000 and Wang Qiangwan are all numbers that are approximately equal to the process, and I can tell you if you need a process.

Li Dong made a profit of 40,000 and Wang Qiang made a profit of 52,000.

The price of 1 fountain pen is as much as the price of 4 ballpoint pens, so the price of 2 fountain pens is as much as the price of 8 ballpoint pens, so the brigade department bought 2 fountain pens and 15 ballpoint pens and paid a total of 92 yuan, which can be converted into buying 23 ballpoint pens and paid a total of 92 yuan, then 1 ballpoint pen is 4 yuan.

Then 1 fountain pen is 16 yuan.

4 (** of a ballpoint pen).

4 4 = 16 (** for a fountain pen).

Because the price of 1 fountain pen is as much as the price of 4 ballpoint pens, so buying 2 fountain pens is equivalent to buying 8 ballpoint pens, so the brigade department bought 2 fountain pens and 15 ballpoint pens, paying a total of 92 yuan, which can be regarded as buying 23 ballpoint pens, and it is easy to find out that the unit price of each ballpoint pen is 4 yuan, so the ** of the fountain pen is 16 yuan!

First of all, the price of 1 fountain pen is as much as the price of 4 ballpoint pens, and it can be known that 2 fountain pens and 15 ballpoint pens are equivalent to 2 4 15 23 ballpoint pens, with 92 23 4 yuan, a ballpoint pen of 4 yuan, and finally with 4 4 16 yuan, a ballpoint pen of 16 yuan.

92 (2*4+15)=4 yuan.

4*4=16 yuan.

A: 16 yuan per pen and 4 yuan per ballpoint pen.

This is a symmetrical figure of 1 2 3 4 5 6 7.

The answer is to symmetrical 6.