高中生英语优秀演讲比赛稿（精选3篇）
i have the answer to a question that we've all asked. the question is, why is it that the letter x represents the unknown? now i know we learned that in math class, but now it's everywhere in the culture -- the x prize, the x-files, project x, tedx. where'd that come from?
about six years ago i decided that i would learn arabic, which turns out to be a supremely logical language. to write a word or a phrase or a sentence in arabic is like crafting an equation, because every part is extremely precise and carries a lot of information. that's one of the reasons so much of what we've come to think of as western science and mathematics and engineering was really worked out in the first few centuries of the common era by the persians and the arabs and the turks.
this includes the little system in arabic called al-jebra. and al-jebr roughly translates to “the system for reconciling disparate parts.“ al-jebr finally came into english as algebra. one example among many.
the arabic texts containing this mathematical wisdom finally made their way to europe -- which is to say spain -- in the 11th and 12th centuries. and when they arrived there was tremendous interest in translating this wisdom into a european language.
but there were problems. one problem is there are some sounds in arabic that just don't make it through a european voice box without lots of practice. trust me on that one. also, those very sounds tend not to be represented by the characters that are available in european languages.
here's one of the culprits. this is the letter sheen, and it makes the sound we think of as sh -- “sh.“ it's also the very first letter of the word shalan, which means “something“ just like the the english word “something“ -- some undefined, unknown thing.
now in arabic, we can make this definite by adding the definite article “al.“ so this is al-shalan -- the unknown thing. and this is a word that appears throughout early mathematics, such as this 10th century derivation of proofs.
the problem for the medieval spanish scholars who were tasked with translating this material is that the letter sheen and the word shalan can't be rendered into spanish because spanish doesn't have that sh, that “sh“ sound. so by convention, they created a rule in which they borrowed the ck sound, “ck“ sound, from the classical greek in the form of the letter kai.
later when this material was translated into a common european language, which is to say latin, they simply replaced the greek kai with the latin x. and once that happened, once this material was in latin, it formed the basis for mathematics textbooks for almost 600 years.
but now we have the answer to our question. why is it that x is the unknown? x is the unknown because you can't say “sh“ in spanish. (laughter) and i thought that was worth sharing.
(applause)
Many people believe that money is the most important thing in life. It seems impossible to live without money in today’s society. With money people can buy bigger house fancy cloths expensive food luxurious cars and travel all around the world. Money leads to a better life and ensure people’s basic needs. Money is also stand for wealth and social status. If one makes countless money then he is a successful man. As to some young girls money is the only measure to access a man. If a man has a new apartment and a new car he will be the “hot stuff” in the girls’ eye. They marry for money rather than for love. Just like the old Chinese saying goes money makes the mare go. Making more money has become a major goal in the eye of some people. They value money more than anything else in the world.
Different people have different opinions of money. Some people spare no effort to make money such as stealing gambling and cheating. They believe money can bring them everything. However I don’t think money can make people really happy or bring people everything. People can not use money to buy health. Steven Jobs the founder of the Apple Company died of cancer. He was a billionaire but he couldn’t use money to buy himself a longer life. And money can not buy the time that already slip away. Money is also a tool for us to exchange materials but not all the stuff. We should have a right attitude towards money. We should earn money by honest means and spend it probably. Only in this way money can make us happy.
Many years ago, there lived a very rich man who wanted to do something for the people of his town. But first he wanted to find out whether they deserved his help. So he placed a very large stone in the center of the main road into town. Then he hid behind a tree and waited. Soon an old man came along with his cow.
"Who put this stone in the center of the road?" said the old man, but he did not try to remove the stone. Instead, with some difficulty
he passed around the stone and continued on his way. Another man came along and did the same thing; then another came, and another. All of them complained about the stone in the center of the road, but not one of them tried to remove it. Late in the afternoon, a young man came along. He saw the stone and said, "The night will be very dark. Some neighbor will come along later in the dark and will fall against the stone. "
The young man then began to move the stone. He pushed and pulled with all his strength to move it to one side. But imagine his surprise when under the stone he found a bag full of money and this message: "This money is for the thoughtful person who removes this stone from the road. That person deserves help."
Hello everyone,today I'm very glad to be here to addrea speech about joking.
As we all feel, we are having a busy life -- busy working,busy studying,busy talking,busy eating,and even,busy falling asleep!In this rapid developing world,we have to be busy or we will fall behind others,but the busy life always bring us more or lesome unpleasent,but luckyly,we have an easy but excelent way to deal with it,that is,to joke!
A funny joke may relax our feelings,ma-ki-ng the busy more enjoyable;a friendly joke may better the atmosphere when two people meet the first time;a humor joke can make others laugh while feeling you are a clever person.
Joking is such a good thing,so remember to crack a joke and keep a happy mood in your busy life.
Thanks.