The Source of EnergyA summary of the physical and chemical nature of life must begin, not on the Earth, but in the Sun; in fact, at the Sun's very center. It is here that is to be found the source of the energy that the Sun constantly pours out into space as light and heat.
This energy is liberated at the center of the Sun as billions upon billions of nuclei of hydrogen atoms collide with each other and fuse together to form nuclei of helium, and in doing so, release some of the energy that is stored in the nuclei of atoms. The output of light and heat of the Sun requires that some 600 million tons of hydrogen be converted into helium in the Sun every second. This the Sun has been doing for several thousands of millions of years.The nuclear energy is released at the Sun's center as high-energy gamma radiation, a form of electromagnetic radiation like light and radio waves, only of very much shorter wavelength. This gamma radiation is absorbed by atoms inside the Sun to be reemitted at slightly longer wavelengths.This radiation, in its turn is absorbed and reemitted. As the energy filters through the layers of the solar interior, it passes through the X-ray part of the spectrum eventually becoming light.
At this stage, it has reached what we call the solar surface, and can escape into space without being absorbed further by solar atoms. A very small fraction of the Sun's light and heat is emitted in such directions that after passing unhindered through interplanetary space, it hits the Earth.
Hello! My name is Chen Danqing. My English name is Joy. I'm 14 years old. I'm a happy girl. I have a happy family. My father and my mother are both office workers. They're busy. But at weekends, they always cook nice food for me. I'm happy in the family. I love my parents and they love me very much.
I'm a student at Dongzhou Middle School. It is very big and beautiful. There are many classroom buildings and office buildings. Besides the buildings, there is a big playground. After school, there are lots of boys playing basketball on it. I think they are happy. There are a lot of flowers and trees in my school. They are beautiful. I like my school. In my school, I have many friends. All my friends are polite and helpful. My friends are all nice to me. They can make me happy. So I like playing with them.
My hobbies are listening to music and reading. I like pop music very much. I dislike sports because I'm not strong. It's hard for me.
I have a happy family, a beautiful school and many nice friends. I enjoy every day.
My First Day on the Campus
I still remember the day when I first came to the college. Being a boy of 17, I was longing for a new life as a college student; but, at the same time, I had no idea what college life would be like.
That morning when the bus carried me to the gate of the college. I was so excited that my heart was beating very fast as if it would leap out of my mouth. From now on, I would be a student of this college. After registration, we were led by an instructor to the dormitory, where, for the first time, we were going to live without parents but roommates. I was so clumsy that I did not know how to make the bed and fix the mosquito net.
In the afternoon, I took a walk around the campus together with my roommates. To think of studying in such a beautiful place made me feel quite proud of myself. As we were walking along, talking and laughing, a voice came into our ears, "Oh, look at these freshmen!" It was our middle-school-students' looking that gave us away. We continued our tour of the college, inspecting every building and every garden until the sun began to set.
In the evening, we sat together, talking about the past and the future. We were so excited that no one wanted to go to bed.