急!!!跪求关于UFO(不明飞行物)的英语资料

Posted 2023-04-28

难度不要太大,高一年级适用,字数在200~300词左右,最好是演讲稿
最好有中文翻译(没有也罢)
拜托帮个忙吧
在此先行谢过
科技类的比较好
最好不要是自己的经历这样的文

UFO
Origin: 1953

It is no coincidence that the first reported sightings of unidentified flying objects came after the revelations of the secret military projects of World War II. America has always been a land of invention, from the cotton gin to the telephone, from the airplane to the Motel (1925). But wartime inventions raised the status of our technology from awe-inspiring to mythic. Working in total secrecy while spending billions of dollars building whole cities and manufacturing plants, the Manhattan Project succeeded in extracting the energy of the atom and building a doomsday weapon. What could not be accomplished by the American military working in secret? What else was being accomplished?

This was the background for sightings of peculiar objects in the skies, beginning in June 1947, in the Southwestern desert area which had so many secret military installations. The objects could be some new super-secret aircraft developed by the U.S. military. Or could they have been developed by some other technologically advanced beings, perhaps from beyond the Earth or the solar system? After all, we now knew that the technology to permit space travel was possible. And these elusive objects traveled far faster and maneuvered far more adroitly than even a jet airplane.

There were many skeptics, however, who considered the objects pie in the sky--or more exactly "flying saucers" (1947), since excited observers had described the objects as saucer-shaped. The name flying saucers caught on, making serious research difficult. As a 1953 book Flying Saucers Have Landed complained, "ever since the cliché 'flying saucer' was coined, the greatest and most exciting mystery of our age has been automatically reduced to the level of a music hall joke."

The believers preferred the solemn government designation unidentified flying object, first used in 1950. But that was a little weighty for everyday use, so in 1953 the acronym UFO was coined to replace it. It has dignified the pursuit of the elusive objects ever since. Those who study them have been known at least since 1959 as ufologists, and their field of study has been ufology. But most people still couldn't find the alien spaceship in the tail of the Hale-Bopp comet of 1997, and the saucers--oops, UFOs--still haven't landed on the White House lawn.

参考资料：www.answers.com

参考技术A One spooky night when I was in bed, I got up for some water. I heard a strange noise. I looked out my back door and saw a big flying saucer! It had blinking lights on it and it also made a loud humming noise.
I woke up my mom and dad. When we all got to the back door, the flying saucer was gone. We all went back to bed. Mom and dad said I must have been dreaming. After I was in bed for a while I heard another strange sound. I jumped up and ran back to the back door. The flying saucer was back and this time it's lights were blinking but it was making no sound.

I watched from the back door and a strange door opened on the side of the flying saucer. There were colorful lights around the door and bright light coming from inside. Then I saw a shadow and it moved. I saw two bright green eyes in the door way and they were moving toward me. The alien walked a few steps away from the saucer. The alien was tall and skinny. His eyes were very big and glowed green in the dark. He was not really scary looking but was sort of friendly. I was not afraid.

The alien saw my kittens. He started to pet them. They were afraid and ran away. All at once he made a soft purring sound and the kittens came running back to see him. This time they let him pet them. I heard lots of purring from the alien and the kittens. It was very funny. I laughed really loud and the alien heard me. He started to walk towards me. I said "hello" and "how are you"? He didn't say anything but he made that purring sound.

Then he turned and walked toward the flower garden. He picked some flowers for samples to take home with him. He smelled them and sneezed very loud. That woke up my parents and also the neighbors. Everyone came to see what the noise was and when they saw the alien, they were a little scarred, especially the kids. The alien was happy and glad that we were there to see him. He smiled and said "I will not harm you." Then he made the purring noise, turned around and walked toward the flying saucer with the flowers.

He stopped and petted the kittens one last time before he went into the flying saucer. The door closed behind him and the lights around it went out. There was a big sound and the saucer began to spin around faster and faster. There were bright lights and lots of smoke. Then it took off and went into the sky. It moved very fast. When it was far, far, away, we couldn't see it anymore.

Everybody talked about the alien for a while. Suddenly my mom looked at the flower garden and saw a strange flower that she had never seen before. It glowed in the dark and changed to all the colors of the rainbow, back and forth. My mom said that this beautiful rainbow flower must have been the aliens special gift to all of us.

The end

跪求,急!用matlab 在分点数同样多的条件下,用梯形和辛普森公式求sinx在...

跪求,急! 用matlab 在分点数同样多的条件下,用梯形和辛普森公式求sinx在0到π/2的定积分. 请写出详细过程,再次对能写出的能人表示感谢. 不要随便回答.

参考技术A 说明,用下面程序时,必须要先确定m的值.
这两个程序都有误差估计.设n=2m+1(这是因为,辛普森公式要求的)梯形公式:h=π/2/2m=π/4m;a=0;b=pi/2;x=a:h:b;y=sin(x);z1=(y(1)+y(n))*h/2;
z2=sum(y(2:n-1))*h;
z=z1+z2,syms
tf=sin(t);
intf=int(f,t,a,b)(计算精确值),
Fs=double(intf),Juewucha8000=abs(z8000-Fs)(计算误差)辛普森公式a=0;b=π/2;;
h=(b-a)/(2*m);
x=a:h:b;
y=sin(x);z1=y(1)+y(2*m+1);
z2=2*sum(y(2:2:2*m));
z3=4*sum(y(3:2:2*m));z=(z1+z2+z3)*h/3,
syms
t,f=exp((-t^2)/2)/(sqrt(2*pi));intf=int(f,t,a,b),
Fs=double(intf);
Juewucha=abs(z-Fs).