Grace is my pen friend. She is a 13-year-old English girl. What's her school life like? Now let's get to know something about the school life in England.

    •Study

    Most students take the school bus to school. Some go to school by train. When they arrive at their classrooms, they put their homework in a box. Then one student will take it to the teachers' office.

    •Lunch

    Students often have lunch at school. The lunch time is usually from 11:30 am to 1:30 pm. They can have free school lunch. They don't have to pay for it.

    •Uniforms

    Students often wear uniforms at school. On their uniforms, you can see the school logo(校徽). They think uniforms are important. When they go on a school trip, they all look the same. So students may not get lost. What's more, students don't need to worry about what to wear every day. Their parents don't have to buy expensive clothes for them, either.

    Imagine you are taking a walk on thebeautiful beach. Just then, your feet step over something and you hear a crack(噼啪声) —an emptyplastic bottle. Things like this are happening more often because of searubbish.

    Studies show that 80% of all the waste isfrom the land. The waste is mainly plastics (塑料制品)which are really hard to degrade (降解). So the rubbishwill remain there for a long time. Some of the pollution is causedaccidentally. For example, about 10,000 product-filled boxes are lost at seaevery year from business ships. Sometimes people just throw things into thewater from boats or land. Many large rubbish areas are formed in the NorthPacific Ocean.

    Thankfully, the situation isn't ignored (忽视). Groups like the National Oceanic and Atmospheric Administration (NOAA)are taking action to help clean the sea. Since 2006,76 projects have clearedout 3,814 metric tons (公吨) of rubbish from the sea.Methods of rubbish cleaning include using machines to remove (移除) the waste away from the surface of sea water. Besides, specialnets are set by the mouths of rivers to stop the rubbish before it reaches thesea. If everyone does his part, sea rubbish seems like a problem that can besolved.

You must have read or heard of the sad love story between Jia Baoyu and Lin Daiyu. But can you imagine the two singing opera in English instead of speaking poetic Chinese?

Jia and Lin are two characters from the classic Chinese novel A Dream of Red Mansions (《红楼梦》), written by Cao Xueqin (1715-1763). Now the book has been made into an English-language opera. After being performed in San Francisco, US, the performance came to Beijing, Changsha and Wuhan in 2017. 

Many of the opera's creators have backgrounds in both Chinese and American cultures, including the director and playwrights (剧作家). Their understanding of both cultures helped them change a Chinese classic into a foreign-language opera. 

The book, which covers the rise and fall of the Jia family, has 120 chapters and hundreds of characters. But opera writer David Henry Hwang cut down the number of characters to just seven. Hwang, a Chinese-American, focused on the love story between Jia and Lin and tried to write a heartbreaking tragedy that everyone would understand. 

The art director Timmy Yip, from Hong Kong, tried to help foreign people understand the characters using costumes and stage settings. He compared Lin to water and gave her a light green costume. When Lin showed up on stage, there was usually water around her on the stage. 

The creators considered it to be a meaningful job to introduce a Chinese classic to Westen audiences. Hwang told China Daily he was happy to "have made a contribution to the land where my parents were born."

I'm Tina，a thirteen-year-old middle school student. Summer vacation is coming. My classmates are talking about their plans（计划）. Here is a survey（调查） about their plans and their favorite activities（活动）. 

My favorite activity is camping with friends. It's a good way for us to relax. We can enjoy the clean air and the quiet life. When camping in the countryside，we can feel the beautiful stars in the dark night. 

Scientists have created an underwater robot that can tell different kinds of pollution at the bottom of the sea. The robot will help clean-up teams find the rubbish and give them a chance to remove the things that can cause the most harm to the environment. 

The robot, which weighs nearly 100 pounds and uses special cameras to take 3D pictures, was created by a team at Skarv Technologies. 

The researchers put their work to the test at a lake. First, the robot swam up and down in rows at about six feet above the lake bed, collecting information with the special cameras. Then a computer turned the information into a map, which showed different kinds of rubbish in different colors. 

A total of 3, 894 objects were found in the lake and divided into different kinds. "There's too much rubbish," a member of the Skarv Technologies team, Fossum, told New Scientist."There's somewhere around 165 to 300 tons of rubbish in the lake."

It is not always possible for clean-up teams to remove all the rubbish they find underwater, because there is something more important to clean. The robot will be used to help the teams find the most harmful things. And the teams spend their time, efforts and money in removing them first. "Glass isn't really polluting," said Fossum. "So if you know there's an area with a lot of glass, you probably can ignore (忽视) that. Instead, you should pay more attention to the things that are putting heavy metals (金属) into the environment."

Besides helping to check the pollution, the robot can also tell the positions of animals in the sea. It can avoid hurting the animals while the clean-up teams remove the rubbish.

You might have seen beautiful rainbows in the sky before. They form when sunlight falls on water drops in the air. But in fact, moonlight can also create rainbows in the same way. They are called "moonbows". They are similar to rainbows, but they are created by moonlight instead of direct sunlight.

Moonbows are less common than rainbows. Different weather and astronomical(天文学的) conditions have to be just right for moonbows to be created.

The moon has to be very low in the sky-only 42 degrees from the horizon(地平线). The moon period has to be a full moon or nearly full. The sky must be very dark for a moonbow to be watched clearly-any bright light can obscure it. Water drops must appear in the air in the opposite direction of the moon.

Moonbows appear on the opposite side of the moon and usually look white to the human eye. This is because their colors are not bright enough to be noticed by the human eye. It is possible, however, to view the colors in a moonbow using long exposure (长时间曝光) photography.

Moonbows more often appear in some locations around the world. Most of these locations usually have waterfalls, which create thin fog in the air. Some of these locations are the Yosemite National Park in California and Cumberland Falls State Resort Park in Kentucky, US; Victoria Falls on the border of Zambia and Zimbabwe; and Waimea in Hawaii, US.

Moonbows do really happen. So at a certain time and a certain place, when a moonbow happens to appear, you can't miss it if you're right there.