What isthe hardest sport in the world? Some people say it's boxing (拳击), because boxing is dangerousand boxers have to be strong and fast. Other people say the hardest sport issoccer.

    However,most people say the hardest sport is the triathlon (三项全能运动). A triathlon is a race thatincludes three sports. First, racers swim. After that they ride bicycles andfinally they run. In the most common triathlon, racers swim 1.5kilometres, bike40 kilometres, and run 10 kilometres. The winner is the person who finishes therace first.

    There isanother kind of triathlon too. It is called the "Ironman Triathlon (铁人三项)". This triathlon is muchlonger. People who finish this triathlon are called "ironmen" or"ironwomen". This is because these people are so strong that theirbodies are just like iron (铁).

    In thepast, there were other races including three sports. However, they didn't usethe word "triathlon". That word was first used to describe a race inCalifornia in 1974.

    Triathlonracers have to train very hard for their races. Many of them swim and run. Alot of people also do things like yoga (瑜伽). They have many different ways to prepare, but they all have thesame goal. They want to be in perfect shape.

    To be anironman or an ironwoman, you have to be strong and smart. You should know howto save energy during the race.

With the development of Chinese and Western cultures, more and more people go to different countries  for  exchanging  and  learning.  So  knowing  more  about the differences becomes so

necessary.

First, Western people express themselves directly, while Chinese act oppositely ( 相 反 地 ). Chinese are implicative (含蓄的) most of the time. When Chinese get angry or unsatisfied (不满的), most of them will say nothing. But if you are unsatisfied with a foreigner, you need to speak it out. Don't hide your feelings because he or she doesn't like it or can't understand your thoughts.

Second, the value about things is different between Chinese and Western people. Chinese seem to be more worried about tomorrow, while Western people like to spend tomorrow's money in advance. Western people believe that they should enjoy themselves at the moment and tomorrow is another day. So they enjoy everything they have now, having no clear plans for the future.

But remember, there is no judgement (评判) about which one is better.When    in    Rome,    do    asthe    Romans    do. We just need to know the differences and learn to understand each other. Every country's culture has its own special meaning. What we need to do is to respect (尊重) each other's

culture and gel along with each other peacefully.

In the Beijing Winter Olympics, we were treated to incredible displays of athletic talents as competitors took to the snow and ice. As a popular sport at the Winter Olympics, ski jumping is one of the best examples to showcase the "superhuman" power of athletes.

Ski jumpers soar into the air and appear to be almost flying in the sky. How do they achieve this? Physics can offer us an explanation of how they make it. It involves the use of the laws of aerodynamics (空气动力学) to fight against gravity and increase lift while reducing drag.

To understand how ski jumping works, we need to consider three elements: gravity, lift and drag. Gravity is the force that pulls us towards an object. Lift occurs when an object is moving through the air—as its surface comes into contact with air particles (微粒), the particles are pushed down and away from the object, allowing it to move up. At the same time, this interaction creates drag, and slows down an object's movement.

While there is nothing that the skiers can do about gravity, they can twist their bodies into positions that allow them to achieve greater lift and avoid as much drag as possible. According to the Smithsonian Magazine, "To do this, athletes try their best to make their skis and body nearly parallel to the ground and place their skis in a V-shape just outside the form of the body. This position increases the surface area that produces lift and puts them in the ideal angle that will also maximize (最大化) lift."

Because of how the sport works, athletes' equipment is strictly controlled according to weight and height in order to avoid any unfair advantages. This means suits must be tight in order to ensure athletes cannot use them as a way to gain more lift. For athletes, minor day-to-day water weight changes as little as 300 grams. It can mean that suits will not be tight enough according to their body mass indexes (体重指数).

Technology plays an important part in our daily life now. Yet not many of us {#blank#}1{#/blank#} how much we rely on it until we compare our lives to those in the past. There was no {#blank#}2{#/blank#} technology at that time，yet the items that people had were quite enough for them to live their lives.

Without necessary cooking tools, the people could still {#blank#}3{#/blank#} to make their food as nice as our food today. Animal parts were thrown away if they were not delicious. Others were cooked over the fire. However，everything they {#blank#}4{#/blank#} was taken from the forests around them.

A few good friends are talking about their last vacations.

I'm a raccoon dog. I lived in the wild. But now, I move to the big city of Shanghai and live close {#blank#}1{#/blank#}people.

These years, many raccoon dogs like me have moved to cities. One big reason is that the cities are greener. It is easy for me {#blank#}2{#/blank#} (find) warm places, water and green space there. I like to live near the bushes and trees {#blank#}3{#/blank#}I can hide myself immediately. For example, last night,I {#blank#}4{#/blank#} (sleep) when a man came up to me. I jumped up a tree quickly. How clever I was!

As for food, when I was in the wild, I {#blank#}5{#/blank#} (have) to try hard to catch mice and rabbits. But now, I can find food in rubbish bins {#blank#}6{#/blank#} (easy). Many people feed stray cats(流浪猫). Sometimes, I can also eat the delicious cat food. Life in the city is very comfortable and convenient. I've got{#blank#}7{#/blank#}(fat) than before.

What's more, many people are kind. They never drive {#blank#}8{#/blank#}(I) away, although they may not be very clear about what animal I am.

But there is also{#blank#}9{#/blank#} problem. Scientists found about 3,000—5,000 of us in Shanghai. Some {#blank#}10{#/blank#}(place) are crowded. Scientists think some of us should move to somewhere else. I hope people will build more parks and we can live with them in peace.