Since the first person walked on the moon in 1969, technology has greatly helped space exploration. In recent years scientists have built a special robot to accompany astronauts on space missions (任务). Because this robot looks and moves like a person, scientists call it a humanoid robot. The latest model of the humanoid robot is known as R2, short for Robonaut 2.

    R2 was first launched into space on February 24, 2011. It was built by the National Aeronautics and Space Administration (NASA) and the car producer General Motors (GM).

    R2 weighs 330 pounds and costs $2.5 million to build. It has arms and a head- filled with vision equipment—but no legs. Its "brain", or computer, is in its stomach. R2's arms can hold 20 pounds. Each bendable finger has 5 pounds of grasping force. R2's hands are also skillful. Since its hands are shaped like human hands, R2 can use human tools to complete tasks traditionally performed by astronauts." Astronauts absolutely have their day packed from the minute they wake up until they go to bed. If Robonaut can provide just an hour's worth of relief to the astronauts doing something they don't want to do, that would make it worth it right there," says Nic Radford, the deputy project manager of R2.

    One advantage of working with R2 will be that ii can't complain about its work! Astronauts will also appreciate the fact that the robot can perform its duties without constant supervision (监管). R2 can be assigned a task and then checked on periodically. If R2 does not complete a task correctly, astronauts will be able to make minor adjustments to adapt (适应) the robot's behavior so that the task gets done right.

    R2 is still in the design stage of development, which means that scientists are frequently testing it and looking for ways to improve it. Right now, humanoid robots do not have the protective equipment needed to work outside the space station. As technology advances, humanoid robots will be able to help astronauts with dangerous tasks as well as routine ones.

    In the future, humanoid robots will be astronauts' eyes in space, going to places considered too difficult or unsafe for astronauts to explore. Some of them will be mounted on wheels to explore the surface of planets or asteroids (小行星). The robots will be able to send back videos and help astronauts gather information about the atmospheres of these places.

    One outcome of using these humanoid robots will be a greater understanding of the interaction between humans and robots. NASA engineers believe that when humans and robots combine forces and work together, the results will be better than what either could achieve alone. John Olson, a director at NASA headquarters in Washington, D.C, says that the project will allow us to go farther and achieve more than we can probably even imagine today.

Hello. I'm Jim. I am thirteen years old and I come from Canada(加拿大). I can speak French（法语） and English. Do you have pen pals（笔友）? I have four.

Project- based learning (项目化学习) is learning while doing. It gives learners the chance to get a deeper understanding of a topic. During the learning, learners solve problems by using real- world examples and challenges. Project- based learning is becoming widely used in schools. Students work on a project over a period of time— from a week to a term. At the end of the project, they show their knowledge and skills by creating a product for people. Let's take the example of Sandra.

Sandra is an eleven- year- old student in Sunshine Primary School. She wanted to know more about Greek mythology (希腊神话). Well, how did she make it?

From the example of Sandra, we can see that project- based learning allows a student to learn about a topic and then create a project based on his or her talents and skills. Not everyone is a great test taker, but everyone is good at something. Through project work, students can not only learn deeply about a topic, but also have fun learning. So if you' re interested in something, why not start with project- based learning?

 Critical thinking(批判性思维) is trying to improve the way you think. People use critical thinking in every area of life to solve problems and evaluate claims(评估主张) Like every other skill, critical thinking takes practice. When a problem comes our way, we need to think critically to decide how to solve it. When we see an advertisement, for example, we should stop and think. Advertisements are made to make people feel certain that they are true, and then people can buy the products. But is what the advertisement says true? Is it making a claim? Or does it only int erest us? Critical thinking is important and stops us from making poor choices. In fact, we are using it if we ask questions naturally about what we see.

 Practice makes perfect. While you are growing in critical thinking, you' ll become a wiser and more thoughtful person. There are many ways of doing practice. Here are a few.

 Read about a topic people disagree on. Look at articles or books on all sides of the subject. For each side of the subject, think carefully and evaluate it.

 When you see or hear a claim, ask questions about it. Who is making the claim and why?

 Evaluate your own thinking. Where and why do you think uncritically? How can you improve? Critical thinking should be part of everything we do. It may help you to succeed at work or school. Make yourself into a habit of critical thinking. Change your thoughts and change your world.

The Grand Canal(大运河), or Da Yunhe, is the world's longest man-made river. It includes three parts, and the Beijing-Hangzhou Canal is the most important one.

It is about 1,800 kilometers long from Beijing to Hangzhou. After running for more than 2,500 years, the canal has become one of the most popular places for tourists.

Last year, all of the canal's dried- up parts were refilled (重新注满) with water. The local government says the 62-kilometr e boat trip will be open to more people soon. It will offer travelers a chance to enjoy nice food and natural wonders at the same time. Moreover, travelers can learn about the culture and old stories through the tour.

The best part along the canal is a group of old buildings in Tongzhou District, Beijing. These buildings cover an area of over 15,000 square meters, including a famous Confucius temple(孔庙). Built in the Yuan Dynasty (朝代), the temple has a history of around 7 centuries. Plenty of travelers enjoy taking photos among those red walls and grey tiles(瓦片) and they feel like they go back to the old times.

The speech bubble* is a way to show words spoken by characters in comics* or cartoons. The birth of the speech bubble was in the seventeenth century in England. Since then, it has been used together with drawn characters. At that time, cartoonists used the speech bubble sometimes. A cartoon called Hogan's Alley began to use it all the time in 1895. In Japan, they still had to wait until the 1930s to have the speech bubble. 

A speech bubble usually has two parts – the bubble and the tail. The bubble has the messages that the character wants to express. The tail helps tell who has spoken the words. So the tail is always pointed to the character. If a character can't be seen in the picture, the tail may be pointed towards the bubble itself.

There are diverse speech bubbles. One of the most common bubbles is the thought bubble. It usually shows what the character is thinking about or an idea in a cloud-shaped or square bubble. How about expressing strong feelings? The jagged edge bubble can help to show anger or excitement. But when you want to make your character express a secret or just whisper some words, a bubble with dashed lines may be the best choice. One of the funniest bubbles is the wavy bubble with a wavy tail. It sends readers the message that the character is so tired.

The speech bubble is necessary for expressing spoken dialogues. Comic artists must carefully choose and place it in order to express the proper meaning and not to puzzle the reader. The proper use helps bring characters on the paper to life, for they have a "voice".