【推荐1】Some people believe that humans could live on the planet Mars by the year 2100. Our own planet, the Earth, is becoming more and more crowded and polluted. It is hoped that people could start again and build a better world on Mars. Here is what life there could be like.

At present, our spacecraft are too slow to carry large numbers of passengers (乘客) to Mars and it would take months. With the development of technology, by the year 2100, the journey might only take about 20 minutes in spacecraft that travel at the speed (速度) of light! However, the spacecraft would travel really fast, so the journey to Mars might be quite uncomfortable. Many people would feel ill.

Humans can’t live without water, air or food. So far, nobody knows if there would be enough water or air on Mars for people. Moreover, scientists are not sure if plants could grow on Mars. Food would most probably be made like pills (药片) and would not keep long.

Compared with life on the earth, life on Mars would be better in some ways. People would have more space. They might live in houses with huge comfortable rooms. Also, robots would do lots of their work so that they could have more time to relax. There would probably be no schools. Every student would study at online schools with “e-teachers”.

Life on Mars would be interesting and challenging (充满挑战的). However, it may take hundreds of years to make it true. So the most important thing we need to do now is to protect our beautiful blue planet-the Earth!

【推荐3】How much do you know about Earth—the planet that we live on? Our knowledge of Earth has been developing since ancient times. However, many puzzles (谜) about Earth remain unsolved. Live Science has published a list of the eight biggest mysteries about Earth. Let’s look at some of them.

Where did water come from?

When it first came into being 4.5 billion years ago, Earth was a dry rock. So where did all of our water come from? Scientists think that it might have arrived in the form of ice by an asteroid (小行星) from outer space that hit our planet. But this idea has not been confirmed (证明) because there is very little related evidence(相关证据) to be studied.

What’s in the core (地核)?

Scientists used to study meteorites (陨石) as small examples of Earth, believing that Earth’s core was made of iron and nickel (镍). However, a later study in the 1950s proved this way to be wrong because it found that Earth would be too light to provide gravity (引力) if its core contained only iron and nickel. Today, scientists continue to bring forward different ideas, but none have been confirmed.

How was the moon born?

Scientists have found that the chemical compositions (成分) of Earth and the Moon are very similar. That suggests that the Moon actually came from Earth. For example, it could be a piece of Earth that separated when Earth hit another planet. It is also possible that when Earth first came into being, it spun (旋转) very fast and threw off enough molten (熔化的) rock to later form the Moon.

【推荐3】To-wit-to-woo, to-wit-to-woo! What’s that strange sound coming from the forest in the moonlight? It’s an owl (猫头鹰), of course!

All day long, seated comfortably on a tree, the owl is sleeping or at least he’s trying to snooze, because it’s sometimes hard to close the eyes with all the sounds made by the little birds and animals in the forest! The owl hunts (捕猎) only at night. When evening comes, the animals all get to a safe place. The owl opens its big, round eyes. Any little animal around had better watch out! The owl mostly eats small animals like mice, but it wouldn't say no to another bird, if it gets the chance!

The owl uses its fantastic hearing to find its food, and then it turns its head from side to side，using its sharp (敏锐的) eyes to follow the animal.

Finally, it flies down to get the animal. Owls have special, soft feathers (羽毛), so they can fly without making any sound. Owls are such good hunters that they can even catch a fly in the air!

The owl is quiet most of the time, except when you get too close to its home. The owl is a great mother, who will protect her babies by opening her feathers angrily. An owl will even hurt people if she thinks her babies are in danger!

An owl has no teeth, so it eats an animal whole. All the parts of the animal that the owl can’t digest (消化) will end up as small pieces. If you find these small pieces, you know you are near an owl’s home.

【推荐2】What will the car be like in the future? Maybe we can sit in a car that can drive itself.

About 40 years ago, scientists from the United States started to make self-driving cars (无人驾驶汽车). The most famous one was made by Google(谷歌) in 2009. There are cameras and radars (雷达) on the top of the car. They let the computer in the car draw a 3D map of the environment(环境). Chinese scientists have also successfully(成功地) made a self-driving car. The car made a trip from Changsha to Wuhan.

Is a self-driving car safe? A recent(最近的) study shows that robots(机器人) make safer drivers than people. If only 10% of cars on the street are self-driving, they will save 1,000 lives (生命) every year. If 90% of vehicles(交通工具) are self-driving, 21,700 lives will be saved(被救) a year. But a self-driving car is expensive and each costs about $100,000. So it is impossible to be very popular in the near future.

When everyone in China is wearing masks (口罩) to stop the COVID-19 (新冠肺炎), many people in Western countries don’t seem to want to do the same. For example, an Italian lawmaker was criticized (批评) by his coworkers when he went to work with a mask. They said he made them nervous. But why do the East and West have different ideas about wearing masks? Let’s take a look.

Western ideas about masks

In the West, people should wear masks only when they get sick, for example. People see masks as a tool (工具) to protect sick people and stop disease from spreading (传播), so healthy people don’t need to wear them. But as the number of COVID-19 cases is growing around the world, people in the West are changing their ideas.

Mask culture in the East

In Asian countries like China and Japan, wearing masks is common. In 1910, Chinese doctor Wu Liande invented (发明) the modern medical mask. During the 2003 SARS epidemic (流行病疫), people in China and East Asia also used masks to protect themselves. 

In Japan, wearing masks shows your politeness (礼貌) when you get a cold or flu. Some Japanese also turn masks into fashion accessories (配饰). They have different colors and patterns to choose to match their clothes. Some young women wear masks when they don’t have their makeup (化妆) on.

Many pop stars in Asia also use masks to protect their privacy (隐私). This cultural and historical background has made it easier for people in the East to wear masks when epidemics break out.