The Long March 5 Y3 is China's strongest rocket.

    China's biggest and most powerful carrier (运载) rocket roared (轰鸣) into space on Dec 27, 2019. The Long March 5 kicked off its mission (任务) at the Wenchang Space Launch Center in Hainan.

    The 57-meter-tall rocket, known as the Long March 5 Y3, is the tallest, strongest and most technologically sophisticated (技术复杂的) rocket in China. Since it is much bigger than China's other Long March rockets, people call it "Fat 5". The rocket is able to carry spacecraft (航天器) weighing up to 25 tons – roughly the weight of 16 midsize cars – into low-Earth orbit (近地轨道), China Daily reported. This payload capacity (有效载荷) is about 2.5 times greater than that of any other Chinese rocket.

    During the December launch, the Long March 5 successfully sent the Shijian 20 experimental satellite into orbit. At more than 8 tons, it is the heaviest and most advanced communications (通信) satellite built by China.

    The launch also tested key technologies that will be used to take the Chang'e 5 probe (探测器) to the moon, according to the China National Space Administration.

    The success of the Long March 5 launch washard-earned. The rocket's first launch was carried out in November 2016 at the Wenchang center. A second mission took place in July 2017 at the same site, but failed to send a satellite into orbit. According to project leaders, in the two years since that failure, the rocket's research team held more than 600 seminars (研讨会) and carried out at least 1,000 experiments and tests to improve the rocket.

    "Compared with the Long March 5 Y2 that was used in the failed second mission, the new one has about 200 technical improvements, including changes to the engine design," Li Dong, the rocket's chief designer (总设计师), said to China Daily.

    The future missions of the Long March 5 will include a trip to Mars, taking back moon samples (样本), and placing parts of a manned (载人的) space station into orbit. 

    Where weredominoes (多米诺骨牌) from?Modern dominoes first showed up in Italy during the 18th century. But it isbelieved that the earliest dominoes were Chinese playing cards. Italianmissionaries (传教士) in China may have brought the gameto Europe. Do you think so?

    Do youlike to play with dominoes? Dominoes are small rectangular (长方形的) pieces made of wood orplastic (塑料). People can place dominoes in differentshapes. Then, they push one domino down and the rest of the dominoes fall oneby one. It is interesting to watch.

    Butplacing dominoes is hard. To make sure the dominoes fall smoothly, the spacebetween each domino is important. According to domino—play. com, if a domino is about 4cm long, then the space between two dominoes should be1—2 cm. If the space is too big, the dominoes will stop falling halfway.If the space is too small, the dominoes will fall too quickly and won't lookinteresting.

    Beginnerscan start by putting dominoes in a straight line. This is the easiest shape.Professional (专业的) playerscan place dominoes in many other shapes, including big circles, beautifulflowers and even famous paintings.

People care a lot about food and their health. What hot words about food and health caught Chinese people's eyes in 2023? Let's see some hot words from the first National Nutrition Literacy Conference (全国营养科普大会) held on Dec 9, 2023.

☆ Pre-made dishes (预制菜)

Pre-made dishes are half-finished or finished dishes. They are already cooked or prepared. However, they may cause health problems. For example, some have too many additives (添加剂). So doctors advise people not to eat too many pre-made dishes.

☆ Nutritional literacy (营养素养)

It shows how well a person can learn and understand nutrition information and skills which are important for making good nutrition decisions.

☆ Dietary regimen (食养)

A plan or set of rules that show what and how much a person should eat to keep in good health.

☆ Aspartame (阿巴斯甜)

It's a sweetener widely used in food to take the place of sugar because it is low in calories (卡路里) and much cheaper than sugar.

And the last one is called an all-encompassing approach to food (大食物观). It means people need to have all kinds of food.

Health comes first. Do you live a healthy life?

①Millions of people around the world cook their food on fire every day.People must spend lots of money on cooking fuel.However，there is a much easier and cheaper way to cook using energy from the sun.

②Solar cookers have been used for centuries.A Swiss scientist made the first solar cooker in 1777.Today，people are using solar cookers in many countries around the world.People use them to cook food and to heat drinking water.

③There are three kinds of solar cookers.The first is a box cooker.It is designed with a special wall that collects sunshine into the box.A box cooker is good for slow cooking of a lot of food.

④The second kind of solar cooker is a panel cooker.It has several flat walls that collect the sunshine onto the food.People can build panel cookers quickly.They do not cost much.In Kenya，for example，panel cookers cost just two dollars.

⑤The third kind of solar cooker is a parabolic（抛物线的） cooker.It has rounded walls that collect sunlight into the bottom of the cooker.Food is cooked quickly in parabolic cookers.However，these cookers are hard to make.They must be moved again and again to follow the sun.Parabolic cookers can also cause burns and eye injuries if they are not used correctly.

⑥You can make solar cookers from boxes or heavy paper.They will not catch fire.Paper burns at 232℃.A solar cooker never gets hotter than that.Solar cookers cook food at low temperatures over long time.This allows people to cook food and do other things at the same time.

Hello，everyone. I'm an AI robot（智能机器人）. My name is ChatGPT. I want to make friends with you. 

I can tell you many things. One day，a boy asks me: "Mike's mom has four boys. Three of them are Jack，Sam and Tim. What is the name of the fourth boy? "The boy thinks it a difficult question. But to me，it is too easy!So I tell him: "Sure. The fourth boy's name is Mike!"He is very happy and he likes to ask me many questions every day，like"Is playing soccer healthy? "，"Why do we like tidy rooms? ""Where is the first library? " Some of the questions sound difficult，but I can always tell him the right answers（回答）. 

I can also write（写） e﹣mails，songs，stories in English and Chinese in a short time. And I can do tests of all subjects and always get good grades（分数）!Do you like it? 

I'm very useful. ▲I can not think like you. I can only answer questions that are in the computer. So I need your help，too.