Have you seen advertisements about hair care products? The models(模特) have shining hair like jewels(宝石). But now making hair shine is no longer the task of hair care products, because hair can be made into real jewels. Believe it or not, a company called LifeGem in the US makes it possible.

    The company is in the business of taking hair from dead people and making them into diamonds(钻石). Now the company plans to make three diamonds using Beethoven's hair to show their latest technology. The work will take about 7 months. In the end, Beethoven's long hair will become three shining diamonds.

    Since the great musician died in 1827, you may wonder where they got Beethoven's hair. A man called John Reznikoff gave the hair to the company. He holds the Guinness World Record for the latest and most valuable collection of celebrity(名人) hair. His collection also includes hair of Napoleon, Albert Einstein, Abraham Lincoln and John F. Kennedy. In total, the collection is worth over five million dollars.

    Though it sounds unbelievable, diamonds made with hair are for the families to remember the dead.

    Have you ever dreamed about sending a letter to yourself or your friends in the future? While express mail(快递) is a fast way to send your letters, there is another type of mail appearing in China as a new business—future mail.

    "The letter should be sent next Mother's Day and not a day earlier!" Lin Xiaofan, a college student in Shanghai, tells one of the companies offering the service.

    Lin Xiaofan wrote the letter to her mother nearly a year earlier to express her love to her mother for next Mother's Day.

    "Offering this service makes people slow down and lets them understand the meaning of 'time' in another way," said Zheng Zhimin, manager at a "future mail" company. Zheng thinks "future mail" letters help remind us of care, friendship and love.

    While "future mail" is becoming more and more popular, some people are wondering what will happen if the postal address changes or if the company goes broken before the letters arrive.

    Zheng said customers are glad to sign a contract(签订合同) to make sure that they can be compensated if their letters are lost or damaged.

    Most of the customers are college students and young white-collar(白领) workers. Psychologists (心理学家) said that young Chinese might have a new way to express their feelings through this service. Most people put their hopes and wishes in the letter so that they can experience the connection(联系) between the past and the present when they receive the letter.

Now students' English handwriting（书法）gets worse and worse. That makes their teachers feel worried. Is your English handwriting beautiful? If not, here are four steps that really work!

u  Using paper with lines (线条)

Using paper with lines can keep you writing straight when you write English words or sentences. Those lines on the paper can help you to write words in the right size.

u  Slow down

If your writing is hard to read, try slowing down a little. For some kids, going slower makes the handwriting clear. If you write too fast, it's hard for you to stop where you should, and even worse, you may make more mistakes.

u  Hold your pencil right

When you hold your pencil the correct way, writing is much easier. Try to be relaxed and don't hold the pencil so hard while writing, and then it makes your handwriting nice and clean. If you do so, people will think you are a student with a good habit.

u  Draw more pictures

Drawing can improve your handwriting. You need to use the skills to control(控制) your pencil better when you are drawing pictures. If you have no time for drawing at school, you can practice it at home.

Some have good handwriting and some don't. Anyway, handwriting is very important. You need to take time to improve it.

Animals and insects have their special way to live in nature. For example, locusts (蝗虫) are very {#blank#}1{#/blank#} food for birds, but it is not always easy for birds to catch them. That is not because locusts are good jumpers or {#blank#}2{#/blank#}. Is that because they are smarter than their enemies (敌人)? The answer is "no". The reason is that the colors of locusts {#blank#}3{#/blank#} with the colors of crops. When crops are young, locusts look green. But when autumn {#blank#}4{#/blank#}, locusts change to the yellow and brown color as crops do.

Brown bears, tigers and other animals move {#blank#}5{#/blank#} through forests. They can't be seen easily by their enemies. This is {#blank#}6{#/blank#} they have the colors like the trees. For the same reason, polar bears are white like the color of {#blank#}7{#/blank#}. Butterflies and bees living among the flowers are colorful like flowers. Soil insects are mostly dark-colored and they live {#blank#}8{#/blank#} the dark and wet soil. However, insects with colors different from plants can easily be {#blank#}9{#/blank#} and eaten by enemies. In order to live, they have to hide {#blank#}10{#/blank#} in the daytime and come out only at night for their safety.

What do you think of their protection?

Are there any lakes in your hometown? What color are they? Around one-third of the world's lakes are blue according to a study in September 2022. But global warming (全球变暖) may lead them to turn green or even brown.

Yang from Southern Methodist University in the US and his team studied the color of over 85,000 lakes based on satellite photos taken from 2013 to 2020. They found that lakes in places with cooler average summer air temperatures—below 19℃—were more likely to be blue than lakes in places with warmer summers.

According to the research, the color of a lake is in part decided by what's in the water. Water takes in the long wavelengths of sunlight, such as red, orange, and yellow, leaving behind the shorter ones like green and mostly blue. In other words, the cleaner the water is, the bluer it looks. In warmer lakes, phytoplankton (浮游植物) develops easily. It has colors from green to brown and red, giving the lake a different color. If global warming continues, one in ten blue lakes might change color, according to the study.

Lakes serve as an important part of our environment, with their color being one of the oldest ways to decide the health of an ecosystem. Humans get their drinking water from lakes, streams and groundwater. As lakes become greener, people may lose lots of clean water. Because of this, treating the water of such lakes becomes more expensive.

At the same time, blue lakes are also a place for people to relax. Some people, according to Catherine O' Reilly, a scientist from the study, considered blue lakes as a place to set their minds free. As these blue lakes disappear, they may feel sad.

If the temperature keeps rising, the fast growing of phytoplankton in greener lakes will provide lake animals more food. However, an increase in these things may also cause some lake animals to die because there is not enough oxygen for them.