What is the sky? How high is it? What color is it? What birds can live above it? These questions are difficult to answer, aren't they? In fact, the sky has no color. Then why does the sky look blue?

    We know that there is air around the world. When planes fly, they need air to lift their wings. Planes can't fly very high. That is because the air gets thinner when they go higher. The same will happen to us if we go high enough. If we go up about 1,200 kilometers from the earth, we'll find no air there. Some birds can fly into the sky as high as a plane, but they cannot fly or live without air.

    Looking up above us, you will see the blue sky with white clouds. It is usually light blue. The color would be bluer when you see on the top of a high mountain. And you will see fewer clouds in the sky between you and the sun. Sometimes the sky doesn't look blue. When the sun rises and falls, you will see red, orange and other colors in the sky, such are the most beautiful moments of the day.

    Who can see the colors of the sky high above the earth? The astronauts! They can see those beautiful colors of the sky from the outer space. However, before flying into the outer space, they sit in a spaceship high above the earth and there is no air at all. The sky would be that dark and its color would be black.

    Now you may understand that we see colors because the air scatters (使散射) the sunlight. Light travels through the air. Without air there would be no colors.

Museum of the Future in Dubai has opened its door to the world. {#blank#}1{#/blank#} You will step into a new world and have a new way of living. You are encouraged to learn life skills that will always be useful to you. {#blank#}2{#/blank#}

You'll have three main experiences there: imagining, designing and building. {#blank#}3{#/blank#} And the activities encourage communication, teamwork and creativity.

{#blank#}4{#/blank#} You must deal with them in given time. These challenges need you to work together with others for a shared goal. If you can solve problems, create something new or try something you've never done before for the future world, you can win a medal.

{#blank#}5{#/blank#}It also shows the actual problems that humans are facing today, like climate change, lack of energy, food safety and mental health. The museum encourages you to become not only a talker, but also a doer (实干家) to help build a better future for humans.

A. There are many challenges for you.

B. My family like to visit the museum every day.

C. The museum is not just about imagining the future.

D. However, you are not allowed to do these activities alone.

E. You are given chances to play and learn through the activities.

F. As a result, you may return to build today's world for the better.

G. It welcomes you to see, touch and experience the life in the future.

Hello, everyone. My name is Jack Brown. I'm 35 years old and I'm from America. I like basketball, football and swimming. But football is my favourite sport, and I can play it very well. I like cooking, too. 

I have two daughters and they are now at St. Paul's School. I work at the school, too. But I'm not a teacher there. What do I do? I'm a cook. I cook lunch for the students there. 

I think it's important to eat the right food and be healthy, so I don't cook food like hamburgers for the students. I cook healthy and delicious food for them. It's not easy to make all the students like the food, but I do what I can do to make the lunch delicious. Many students say that they like the food. I'm really happy about that. 

 What does taking the train mean to you? Perhaps it's just a way of getting to {#blank#}1{#/blank#}( you) destination(目的地). In fact, the train itself can be part of the fun.

 On March 28, China's {#blank#}2{#/blank#}(one) panda- themed tourist train left Chengdu in Sichuan for Zunyi in Guizhou. It soon became the talk of China with its special design (设计) and {#blank#}3{#/blank#}( comfort) service. It's one of {#blank#}4{#/blank#} most interesting trains in China.

 Its inside and outside are decorated with giant panda {#blank#}5{#/blank#}(picture). Attendants(乘务员) carry panda toys and passengers can try panda- shaped food, as well as Sichuan snacks.{#blank#}6{#/blank#} there are many kinds of rooms to have fun, some people call it a" mobile star hotel". Passengers can take showers and use its 5G network as well. This excellent service is one thing that has {#blank#}7{#/blank#}(excite) travelers. And train travel fascinates people for other reasons.

 In the fast- paced times we live in, train travel is a good way {#blank#}8{#/blank#}(slow) down. It gives you time and space to read, sleep, chat with friends, or {#blank#}9{#/blank#}(simple) do nothing but watch the changing views outside. Train travel is also full {#blank#}10{#/blank#} surprises. You might meet new people and become friends with them.

Flu season is coming!Are you prepared？Here are answers to your question!

{#blank#}1{#/blank#}

The flu is a virus（病毒） that passes easily from person to person.Usually the flu appears in winter and the rainy season.

{#blank#}2{#/blank#}

In fact，they come from different viruses.Although the symptoms（症状） can be almost the same，flu symptoms are more serious.Cold symptoms only last about seven days while the flu can last two weeks.

{#blank#}3{#/blank#}

The seasonal flu is very common all over the world.Children，old people and people in poor health catch the flu easily.In the United States，five to twenty percent of the people pet the flu every year.

{#blank#}4{#/blank#}

The flu is pretty dangerous.It can give you fever（发烧） or even make you die.Every year in the U.S.，36

{#blank#}5{#/blank#}

There are many things you can do to keep healthy and stay away from the flu.For example，wash your hands often.Moreover，don't touch your eyes，noses or mouth with your dirty hands.

Do you ever feel like there's not enough time in the day? That time is somehow racing away from you, and it is impossible to fit everything in. But then. you step outside into the countryside and suddenly everything seems slower, more relaxed, like time has somehow changed. It's not just you-recent research showed nature can control our sense of time.

Richardo Correia, the researcher at the University of Finland, found that being in nature may change how we experience time and perhaps, even give us the sense of time abundance(充裕). Correia compared people's experiences of time when they performed different types of tasks in cities and natural environments. It showed that people reported a sense of expanded time when they were in nature compared to when they were in cities. For example, a walk through the countryside felt longer than a city walk of the same distance.

It's not just our sense of time in the moment which appears to be changed by the natural world, and it's alsoour sense of the past and future. Earlier research shows that spending time in nature helps to move our focus from44the immediate(目前的) moment towards our future needs. So rather than focusing on the stress of the demands(需求)on our time, nature helps us to see the bigger picture. This can help us focus on what's important so that we meet our long-term goals. This is partly because spending time in nature appears to make us less impulsive(冲动的)，enabling us to think more about future benefits instead of wanting immediate ones.