Good words, good sentences, 20 good words and 2 good sentences in the fifth lesson of the sixth grade Chinese book of people's Education Press

Good words, good sentences, 20 good words and 2 good sentences in the fifth lesson of the sixth grade Chinese book of people's Education Press

Zhan Tianyou's obstruction at Juyongguan, scorn at the cliffs of high mountains and deep streams, laugh at the survey, resolutely encourage the wind and howl, climb the mountains and cross the mountains, laugh at the excavation of tunnels, scorn the completion of forks on steep slopes, and praise with contempt
Where to build a mountain, where to build a bridge, where to level the steep slope, where to reduce the curvature, we have to go through survey and careful calculation
During the day, he climbs mountains and mountains to survey the route. At night, he draws and calculates under the oil lamp

After the third lesson of the sixth grade volume I of PEP Chinese textbook

Today, I came to the ant kingdom again with great interest, and saw them bustling back and forth. Ants stand in rows, are they ready to do exercises? Suddenly, a big ant rushed out of the house in a hurry, and kept saying: "late, late!". "Plop"! No, a small ant was hit by a big ant

The retelling of Lesson 13 {Cowherd and Weaver Girl} in the first volume of sixth grade of Jiangsu Education Press
More than 200 words

Summarize the meaning of the seventh natural paragraph of "Cowherd and Weaver Girl" in Lesson 13 of sixth grade volume I of Jiangsu Education Press
One day, the cowherd went to feed the cow. The old cow spoke again, and his eyes were full of tears. He said, "I can't help you work in the field. We'll break up soon. After I die, you peel off my skin and keep it. In case of emergency, you put on my skin..." Lao Niu died before he finished speaking

It means that the old cow is reluctant to give up the cowherd before he dies and let the cowherd peel off the old cow's skin after he dies for use from time to time. It reflects the old cow's wish to help the cowherd at the end of his life

How to connect the moment of inertia, angular velocity and kinetic energy?

This can be deduced from the expression of the kinetic energy of the particle
Kinetic energy of particle e = (1 / 2) m * V ^ 2 (1)
For a rotating rigid body, it can be regarded as a system of continuous particles
For a particle on a rotating rigid body, its kinetic energy
E1=(1/2)m1v^2=(1/2)m1*ω^2*r^2 （2）
The kinetic energy of a rotating rigid body is equal to the sum of the kinetic energy of all particles
E=∑Ei=(1/2)ω^2∑mi*ri^2 （3）
Let ∑ mi * RI ^ 2 = IC IC --- be called moment of inertia (for a specified axis of rotation)
Then (3) can be written as
Kinetic energy of rotating rigid body e = (1 / 2) ic * ω ^ 2 (4)
It can be seen that the forms of (1) and (4) are the same

If the sum of the first n terms of the arithmetic sequence {an} is Sn and 6s5-5s3 = 5, then A4=______ ．

∵ Sn = Na1 + 12n (n-1) d ∵ S5 = 5A1 + 10d, S3 = 3A1 + 3D ∵ 6s5-5s3 = 30a1 + 60d - (15a1 + 15d) = 15a1 + 45d = 15 (a1 + 3D) = 15a4 = 5, the solution is A4 = 13, so the answer is: 13

A car running along a straight road, when passing a intersection, its speed is 36km / h. After passing the intersection, it accelerates at an acceleration of 2m / s for 3S

What do you ask is the acceleration speed or displacement after three seconds?
36km/h=3.6m/s
If we find the velocity, then it is
v=V0+at=10+2*3=16m/s
The displacement is
S=V0t+1/2at2=10*2+1/2*2*3*3=29m

Please ask him to call me back when he comes back. I'm his friend Xiao Li?

Please help me ask him to call me back when he come back,I'm his friend Xiaoli

If the lengths of the two sides of the triangle are 6 and 7 respectively, the value range of the third side length a is______ ．

According to the trilateral relationship of the triangle, 1 < a < 13

As shown in the figure, the line segments a, B and C are known. Use a compass and a ruler to make the line segments equal to a + 2b-c

Steps:
Start with a and draw a ray with a ruler
Use a compass to measure the length of a, draw an arc with a as the center, intersect with the ray and point B
Take B as the center of the circle and B as the radius to draw the arc intersection with B1
Take B1 as the center, B as the radius intersection and B2
Take B2 as the center, C as the radius, intersect with C
As shown in the figure above (sweat!), the line AC is the required value