The word“day” has two meanings. When we talk about the number of days in a year,  we are using “day” to mean 24 hours. But when we talk about day and night,  we are using“day” to mean the time between sunrise and sunset. Since the earth looks like a ball,  the sun can shine on only half of it at a time. Always one half of the earth is having day and the other half night. A place is moved from day into night and from night into day over and over by the spinning（旋转）of the earth. At the equator（赤道）day and night are sometimes the same length（长度）. They are each twelve hours long. The sun rises at 6 o'clock in the morning and sets at 6 o'clock in the evening. For six months the North Pole is tilted（倾斜）toward the sun. In those months the Northern Hemisphere（半球）gets more hours of sunlight than the Southern Hemisphere. Days are longer than nights. South of the equator nights are longer than days. For the other six months the North Pole is tilted away from the sun. Then the Southern Hemisphere gets more sunlight. Days are longer than nights. North of the equator nights are longer than days. Winter is the season of long nights. Summer is the season of long days.

    Canada is the second largest country in the world. It is over 7，000 kilometers from the 1 coast（海岸）to the east. It 2 six time zones. 3 it is 9 a. m. in Vancouver on the west coast，it is 1：30 p.m. in St John's on the east coast.

    English and French 4 the two main languages in Canada. About 60 percent of 5 people speak English， and about 25 percent speak French. More 6 70 percent of its population live in cities near the US border（边境）.

    Ottawa is the capital. Every year millions of tourists go there to7 museums and take part in the cultural（文化的）activities. Toronto is the largest city of the country 8 about 2. 5 million people. Montreal is 9 second biggest French-speaking city in the world.

    The maple leaf is the national symbol of Canada. The Canadian flag has a red maple leaf on a red 10 white background.

    Heritage (遗产) is traditional customs, history and beliefs. We use the word “heritage” in many different ways. People talk about their family heritage, city heritage and national heritage.

    Today, heritage is changing. The Internet connects people around the world. In many ways this is a good thing, because we can learn about the heritage of other countries, and we can show our own heritage to the world. However, some people worry that traditional heritage is disappearing. In many ways, countries are becoming more and more alike(相似的).In most countries around the world, you can find KFC. Nike shoes, Starbucks coffee. American movies and so on. Some people think this is a good change, and others don't like it. You can decide whether or not it's a good thing.

    However, everyone wants to protect traditional heritage, and sometimes this is hard. For example, when a new KFC opens in your city, a traditional restaurant might have to close.

    That is why heritage protection is so important. Heritage protection is a simple thought. It means keeping your country's or your city's heritage alive. People do this in many ways. The biggest part of heritage protection is probably preserving (保护)old buildings. Some suggestions of heritage protection are making sure your kids speak your traditional language, and teaching knowledge about heritage to them.

    The world is changing. No matter how it changes, never forget the heritage of our parents and grandparents.

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    My parents have always said that they never felt comfortable traveling by train when they were my age. It's always a mystery to me when they talk about the crowded and noisy train compartments*, wheels clicking on the rails, and the boring and tiring journeys.

However, train travel is quite a different experience today, especially after high--speed rail was widely put into service in China. Nothing can match train journeys for the comfort and speed. Few things could be more impressive than China's high--speed rail system, especially the speed at which it developed—and is still developing. Such speed is known as "China speed".

    China speed means a lot to the country. The past 30 years have witnessed China's rapid development in various areas, like the economy and technology. We've seen dozens of tall buildings appear almost overnight, with roads and highways connecting every comer. And mobile payments and online shopping are playing increasingly important roles in everyone's life. China speed has changed our country and impressed the world. But as we enjoy the benefits of China speed, the problems it brings us can't be ignored, such as the air pollution or traffic problems. As a high price is being paid, maybe we should think about what China speed will bring us in the next 30 years. We need to know that our future depends on the choices we make today, so it is our duty to give China speed a new definition. If you pay close attention to the word "speed", you might notice that each letter stands for something interesting: Society, Progress, Economy, Environment and Development. Our society's progress depends largely on the balance among our economy, the environment, and the development of our future. That is what we need to keep in mind as China continues to speed ahead.

Doorbells are the bells (铃) for people to ring at a door. When someone hears it, he or she can open the door. Do you know that you can ring a doorbell for fish, too? 

Every spring, millions of fish migrate (洄游) along the river in the city to find better places to lay eggs. But in the river, there are many locks (水闸). They stop fish from swimming through. Weerd Lock is in Utrecht, the fourth largest city in the Netherlands (荷兰). When fish get there, they have to wait a long time before the lock opens for boats to pass through. The lock keeper there is glad to open the lock for fish, but he cannot tell when fish want to get through. So in 2021, Mark van Heukelum, a scientist, came up with a good idea to help solve this problem—by using the fish doorbell. 

Under the water near the lock, there's a camera. People from around the world can visit a website (网站) to see fish through the camera. When you see a group of fish waiting, you can ring the doorbell on the screen. And when the lock keeper notices it, he will open the lock for the fish. 

In its first spring season in 2021, people around the world rang the fish doorbell more than 100,000 times. If you want to join them to help fish, visit the website and ring the fish doorbell next spring.