How much do you know about the bird world?

    Birds use three gaits: walking, running and hopping．

    In walking, the left and the right feet move in turn (轮流)．Each foot is on the ground for more than half the time, so there are more times when both feet are on the ground．In running, each foot is on the ground for less than half the time, and there are more times when both feet are off the ground．In hopping, the feet move almost at the same time．This means that for much of the time both feet are off the ground．

    Middle-sized and large birds walk at low speed and either run or hop at higher speed．Small birds, such as sparrows and swallows, usually do not walk, because walking may be too slow for them．It seems that the more time a bird spends in trees, the more likely it is to hop．Perhaps there is wide space in a tree between one thin branch (树枝) and the next, so walking is not a good choice, while on each small branch there is enough room to set both feet down side by side, so hopping seems to make sense．

    Lasers（激光） have many uses including improving someone's eyesight, playing DVDs, cutting the diamonds（钻石） and the list goes on and on. Now, there could be a new use for this powerful tool-changing the weather!

    The Swiss scientist Jean Pierre Wolf is working on using laser beams（激光束） to change the weather for the better. He wants to use it to help stop climate（气候） change. Sounds crazy, right? Well, there is already something kind of like it.

    Cloud seeding（云催化） is a way people stop rain from falling. It uses rockets to release chemicals into the atmosphere（大气层）, but it's not known what this might do to the environment. So Professor Wolf wants to find a better way to do this, and a laser is a good choice since the only thing it uses is light, not chemicals. But how would it work? According to CNN, it would make new clouds. The laser would make condensation（冷凝） happen, in other words producing drops of water. And then the water would turn into really small pieces of ice. Then clouds start to be made just naturally.

    Professor Wolf's hope is to help control the weather in places like California that can face both heavy floods and droughts（干旱）.They are also trying to use lasers to control lightning. Using lasers to change the weather has been tested in a lab, and they have been quite successful in some fields. They are still trying to find out how to use it in the real world, but it could be a new way to stop climate change. "Every time you think you have done everything you can with lasers, something new comes up," said Professor Wolf. "It's quite amazing."

We all know that being kind can help people in need, but do you know that kindness can also help yourself? 

According to National Public Radio, the Big Joy Project began in 2021. It spreads the message that people can find happiness in difficult times and use it to do good. 

The project was open to anyone. More than 70, 000 people from over 200 countries took part in it. All had to take an online survey answering questions about their feelings. Then, they needed to do a small thing every day, such as visiting an elderly neighbor or buying a cup of coffee for a stranger. Finally, they had to take the other survey to compare their feelings before and after.

The results were announced on November 11, 2023. "We are really excited. Aner the project, there are big changes, including greater happiness, less stress, better sleep, stronger problem-solving abilities, and greater satisfaction with relationships," said Emiliana Simon-Thomas, the leader of the Big Joy Project. 

"Think of happiness as a skill that you can get through practice, instead of seeing it as something that happens to you. This may make sense, "added Emiliana. 

Will the changes brought about by doing good last long or disappear soon? The question is not yet answerable. But one thing is certain—doing one good thing can lead to other good things. That's why small acts of kindness can go a long way. 

Today, people want to keep healthy through sports and exercise. But some of them have some wrong ideas about it. "A plate of chicken is a good meal before games because it has much energy."

In fact, the best meal before games should have carbohydrates（碳水化合物）. Food like potatoes, bread, bananas are rich in it, but chicken and meat are not.

"The best time to exercise is early in the morning."

No. Morning is a good time to exercise, but it may not be suitable for you. If an afternoon or evening is suitable for you, and you enjoy the feeling of getting healthier, you can choose any time to exercise. So there is no fixed time for you to exercise.

"If you drink water when you exercise, you'll feel tired."

The fact is that you must have some water during breaks（休息时间）when you exercise. And after exercising, you must have enough water. If you don't drink enough water, then you may feel tired.

"Exercising every day is quite important."

Wrong. Too much exercise is bad for your health. You need to give your body a day of rest.

Know the meaning of success. You cannot have success if you don't know what it means to you. Set clear goals and be realistic (实际的). Make sure your goals can be achieved, or you will spend all your time running after an unclear goal. 

Learn from successful people. Look aroundwho has the success that you are interested in? What are they doing? How do they make a successful life?  {#blank#}1{#/blank#}   Ask them for advice. Spend time around them if you can. Learn from them. They will bring you much meaningful experience. 

Don't be afraid of risks. Successful people think big and act big. It can be hard to do, but if you don't, then how will you ever be successful?{#blank#}2{#/blank#} Dig them out. Successful people experience some degree of risks. Study your risks, and be brave. 

 {#blank#}3{#/blank#}Successful people like solving problems and answering questions. No matter where you are or what you are doing, look around and try to think of ways you can find. For example, what are people fighting with or complaining(抱怨) about? How can you make life easier for them in a good way?

 {#blank#}4{#/blank#} You should learn to hold on. It is also the key to success. Thomas Edison ever said, "I have not failed. I've just found 10, 000 ways that won't work. " So if your first try doesn't work, don't give up.

What else can you do to be successful? {#blank#}5{#/blank#}

A park, a bus station, a cafe ... These are the favorite places for American kids to hang out (闲逛) after school. US kids have short school days. Their parents are busy at work day and night. So kids have too much free time to hang out. Sometimes, they sit on the grass in the park and talk. Sometimes, they just watch the cars drive by and do nothing.

 Is hanging out too much a waste (浪费) of time? Maybe. I wasted a lot of time at a young age! But it was fun. Now, I spend my free time doing exercises. I am also learning new languages, such as Chinese and French. First, I found it hard to learn Chinese. Day by day, I could say some easy words. I think Chinese is more interesting than English. I feel happy about myself. I have fun in learning Chinese in my free time. Two years later, I want to go to the university in China. I want to know more about China.