Write a person's composition, highlighting a feature.

He is a man of strong will. The strong-willed wintersweet is known as challenging winter. And Cheng Xiao's strong personality will also become the paving stone for his success. Among my friends, there are many people with different personalities: introverted, cheerful and optimistic … but what I admire most is that kind of strong personality. Cheng is such a person, from writing to learning, never give up, never give up. I have never seen him cry since I made friends with him all these years. From him, I learned what is strong. Cheng, a black and thin boy, has heavy eyebrows and big eyes that reveal a kind of unyielding power. It is such a boy who told me what is called "clank of iron". In the last school sports meeting, he submitted 1800 meters to challenge himself. At the command, the players are like arrows. He flew away, but before he ran a few laps, he was exhausted and panting. Everyone advised him: "stop running, you will fall!" " "But he kept running, until later, he finally fell down with a" poof ". Although he failed in this competition, he explained to us the true meaning of being strong and unyielding. After class, I accidentally hit my head on the corner of the table. I bulged a big bag, but I didn't hear the word "pain". In math class, the teacher set a difficult problem for us to solve by ourselves. No one can work it out until class is over. Many people chose to give up, only he persisted. Look at him, with his chin in one hand and a pen in the other, constantly calculating on the draft paper, frowning and muttering, as if he would never stop until school was over. His classmates were laughing at him, and he totally ignored him. The next morning, unexpectedly, he really got the right answer. He can lock himself in his room for more than two hours to tie Chinese knots. He can come to school at six o'clock every morning to learn to sweep the floor ... If difficulties are a river, then his strong character is a boat that carries him across the ocean; If difficulty is a tree, then his strong character is a knife to sharpen his thorns; If difficulty is a mountain, then his strong character is an axe to help him climb it. The strong-willed wintersweet is known as challenging winter. And Cheng Xiao's strong personality will also become the paving stone for his success.