English translation Come on, it's tonight!

English translation Come on, it's tonight!

People always remember what they were doing when they heard about important historical events. In the United States, for example, many people were doing on April 4, 1968. This is one of the most important things in modern American history. On that day, Dr. Martin Luther King was killed in Memphis, although people may not remember who killed the doctor, They remember what they were doing when they heard the news
Even the most common activities seem to matter. Robert Allen is now in his 40s. He was a student at the time, But he remembered what he was doing when he heard the news. "It was a bright, sunny day," Robert recalled. "We were playing on the playground when the bell rang. Our teacher told us to stop our work and let us listen to him. He told us the news." Dr. Martin Luther King was killed ten minutes ago! "We couldn't believe it School closed that day, and Robert and his friends walked home in silence
Dr. Martin Luther King's murder occurred 30 years ago, older than many Americans. However, recently, many Americans remember what they were doing when the world trade center in New York was attacked by terrorists. Even the date - September 11, 2001 - has a special meaning for Americans
Of course, not all major events in history are as bad as this. Many Americans still say they remember what they were doing when humans first set foot on the moon on July 20, 1969, Many Chinese people remember what they were doing when Yang Liwei became the first Chinese astronaut. Yang Liwei stepped into space on October 15, 2003. He continued to fly around the earth for about 22 hours. When he returned to the earth, he became a national hero of China and became famous all over the world
Is it this one?

English translation
Urgent need

Whether we are rich or poor, young or old, we all have problems. If we don't deal with our problems, we may be unhappy. Worrying about our problems may affect our performance in school. It may also affect the way we deal with our families. So how do we deal with our problems?
Learn to forget
Most of us may have been angry with our teachers, friends and parents. Maybe they said something you don't like or you feel they are unfair. Sometimes, people are angry about a problem for several years. As time goes by, good friendships may be lost. However, when we are angry, we are usually the affected people ourselves. Maybe we have seen children playing together When they have different opinions and decide not to talk to each other, it usually doesn't last long, which is an important lesson for us: we solve problems by learning to forget
Think of problems as challenges
Many students often complain about the school. Sometimes they have too much homework to do. Or they think the school rules are too strict. We must learn to see these problems as challenges. Education is an important part of our development. As young people, our responsibility is to try our best to meet every challenge in our education with the help of our teachers
Think of something worse
If you compare yourself with others, you will find that your problems are not so terrible. For example, think of Steven Hawking, a very intelligent and capable scientist, who regards many physical problems as unimportant. He can't walk or even speak, but he is very famous and successful. We are likely to be very healthy and smart. Let's not worry about our problems, We have to face the challenge

English translation
What Do No.5 High School Students Do in Their Free Time?
Last month we asked our students about their free time activities.Our questions were about exercise,use of the Internet and watching TV.Here are the results.
We found that only fifteen percent of our students exercise every day.Forty -five percent exercise four to six times a week.Twenty percent exercise only one to three times a week.And twenty percent do not exercise at all.
We all know that many students often go online,but we were surprised that ninety percent of them use the Internet every day.The other ten percent use it at least three or four times a week.Most students use it for fun and not for homework.
The answer to our questions about watching television were also interesting.Only two percent of the students watch TV one to three times a week.Thirteen percent watch TV four to six times a week.And eighty-five percent watch TV every day!Although many students like to watch sports,game shows are the most popular.
It is good to relax by using the Internet or watching game shows,but we think the best way to relax is through exercise.It is healthy for the mind and the body.Exercise such as playing sports is fun,and you can spend time with your friends and family as you play together.And remember,“old habits die hard”.So start exercising before it’s too late!

Last month, we asked students about their free time activities. Our questions were about sports, using the Internet and watching TV. Here is the result. We found that only 15% of the students exercise every day. 45% of the students exercise four to six times a week

What is the density of copper in kilogram per cubic meter

8.9 × 10 ^ 3kg / m3

The addition and subtraction of integers can be attributed to []]

Removing brackets and merging congeners
I have done this problem

What are the meanings of double integral, triple integral, curve integral and surface integral?
Geometry and physics and so on... As popular as possible

LZ first of all, we should know that the meaning of integral is summation
Let's take a physical example. For example, we need to know the total charge distribution f (R)
If it is distributed in a plane, it is a double integral, R can be expressed by X, y
If it's a spatial distribution, it's a triple integral
For the curve integral, it is to sum around a path. For example, a rope with uneven density requires its total mass. It is a curve integral
These all want oneself to experience

What is the rate of advance in volume units? Why?

The advance rate of volume unit is 1000, because volume is the third power of side length. For example, 1m cubic meter = 1000 cubic meters, decimeter = 1000000 cubic centimeters

Square of a + square of B = square of 2C
A is any positive integer, corresponding to a there must be B and C two positive integers
How to prove it
(ABC is not equal)
Answer up to catch up with 50 points

The square of 2C, which is 2C square or 2 * C square
I don't know. If it's 2 * C squared
Let B = 7a, C = 5A
If it's 2C squared, that's 4C ^ 2. Move it right, then (2C + b) (2C-B) = a ^ 2
If it is true, then let 2C + B = k ^ 2 (2C-B), (k is a positive integer greater than 1). So we get 2 (k ^ 2-1) C = (k ^ 2 + 1) B, and K (2C-B) = a, substituting, finally, (k ^ 2-1) / 2k and (k ^ 2 + 1) / 4K are positive integers, and K is a positive integer. We can see that there is no existence
In other words, the problem is the square of 2 * C, B = 7a, C = 5a, so it must exist

It is known that the distance between a point whose abscissa is - 3 and its focus on the parabola C: y ^ 2 = - 2px (P > 0) is 4
Let the moving straight line y = K (x + 2) intersect the parabola C at two points a and B. question: does there exist a fixed point m on the x-axis which has nothing to do with the de value of K, so that ∠ AMB is bisected by the x-axis? If it exists, find out the coordinates of point m; if not, explain the reason

A:
The parabola C: y ^ 2 = - 2px (P > 0) opens to the left, and the axis of symmetry is the X axis
If the distance from the point on the abscissa x = - 3 to its focus is 4, then the distance to the guide line x = P / 2 is also 4
So: P / 2 - (- 3) = 4
The solution is: P = 2
y^2=-4x
The straight line y = K (x + 2) passes through the fixed point (- 2,0) and is the focus F of the parabola
Simulink: y ^ 2 = (k ^ 2) (x + 2) ^ 2 = - 4x
It is concluded that: (k ^ 2) x ^ 2 + 4 (k ^ 2 + 1) x + 4K ^ 2 = 0
According to Weida's theorem:
x1+x2=-4(k^2+1)/k^2=-4-4/k^2
x1*x2=4
If the x-axis is the bisector of ∠ AMB, the slopes of MB and Ma are opposite to each other
Let m be (m, 0)
KMB = - KMA
(y1-0)/(x1-m)=-(y2-0)/(x2-m)
k(x1+2)/(x1-m)=-k(x2+2)/(x2-m)
Obviously, when k = 0, y = 0 has only one intersection with the parabola, which is not in line with the meaning of the problem
So: (x1 + 2) / (x1-m) = - (x2 + 2) / (x2-m)
x1x2-mx1+2x2-2m=-x1x2-2x1+mx2+2m
2x1x2-(x1+x2+4)m+2(x1+x2)=0
8-(-4/k^2)m-8-8/k^2=0
So: 4m / K ^ 2-8 / K ^ 2 = 0
So: when 4m-8 = 0, the constant holds
The solution is m = 2
So: the fixed point m is (2,0)

How to convert force unit and weight unit?

9.8 newton equals one kilogram!
But in general, 10 Newton is equal to one kilogram!