C

    I'm a 34-year-old man. I lived in a nice house and have a successful career. But my life was not always so great. I had trouble learning from an early age. The school life was difficult for me.

    My life improved quickly when I discovered art. The art world gave me a chance to express myself without words. I went to an art school and became good at making things with dough. Here I learned my first important lesson: although I had trouble learning, I could still be smart and well express myself with dough. And I became confident from then on.

    I got my next lesson from rock climbing. It was a fun thing but I was frightened from the start. After about five years of climbing, I learned that if you fall in love with something and do it all the time, you will get better at it.

    Later I decided to learn how to read. Every day I practiced reading. After two hard years, I did well in it. And reading changed my life a lot.

    After learning art, rock climbing, and reading, now I've learnt that when we face difficulties, we should not give up. God closes a door for you, and will open another window for you.

    Life is full of surprises and you never know how things will turn out.

    Sir John Gurdon is a good example of this. As a boy, he was told he was hopeless at science and finished bottom of his class. However , the very same Gurdon shared the 2012 Nobel Prize in Medicine with Japanese stem cell (干细胞) researcher Shinya Yamanaka.

    Like so many scientists, Gurdon shows us where the power of curiosity and perseverance (坚持不懈) can lead.

    At the age of 15 in 1948, Gurdon ranked last out of the 250 boys at his high school in biology and every other science subject. Gurdon's high school science teacher even said that his dream of becoming a scientist was " quite ridiculous".

    In spite of his teacher's criticisms, Gurdon followed his curiosity and kept working hard. He went to the lab early and left later than anyone else. He experienced thousands of failures.

    "My own belief is that we will, in the end, understand everything about how cells actually work," Gurdon said.

    In 1962 ,Gurdon took a cell from an adult frog and moved its genetic( 基因的 ) information into an egg cell . The egg cell then grew into a clone(克隆) of the adult frog. This technique later helped to create Dolly the sheep in 1996,the first cloned mammal(哺乳动物) in the world.

    In 2006, Gurdon's work was developed by Yamanaka to show that a sample (样本) of a person's skin can be used to create stem cells. Using the technique, doctors can repair a patient's heart after a heart attack.

    "Luck favors the prepared mind," Gurdon told the Nobel Prize Organization. "Ninety percent of the time things don't work ,but when they do ,you have to seize(抓住) the chance. "

What is the most stressful thing in school? It is probably exams. Exams can put us under a lot of pressure. But some students do well under pressure while others feel terrible. {#blank#}1{#/blank#}

It all comes down to dopamine (多巴胺). {#blank#}2{#/blank#} It has many important roles: influencing memory, attention. and how we learn. Our brains work best when there is an even balance of dopamine—not too much or too little. The brain controls dopamine in two ways. It either takes out dopamine quickly, or gradually. Exam success can be related to how fast dopamine goes back to an even balance.

 {#blank#}3{#/blank#} if you become stressed, your brain will start to have too much dopamine. {#blank#}4{#/blank#} The quicker you are able to go back to an even balance of dopamine, the quicker you can fix yourself perform better on a test. 

Scientists found that, during a test, people who slowly got back to an even balance of dopamine scored 8 percent lower. {#blank#}5{#/blank#} The answer is yes. So don't fear, there is some good news. The study also found that the more practice you get, the less stressed you'll be. So, it turns out that practice really does make perfect.

A．What happens when we sit for an exam?

B．It is like a cup flowing over with water.

C．So, why do some students perform better under stress?

D．That's the difference between a good mark and a bad mark.

E．Dopamine is a chemical in our brain that sends information to our body.

F．Is there anything that can help change the speed of dopamine getting into our body?