1 . Have you wondered how dogs became man's best friends? On October 30, a study published in the online journal Science revealed more information about the history between dogs and humans, dating back thousands of years.

From previous studies, it was known that sometime between 15,000 to 40,000 years ago, humans first encountered a friendly gray wolf, and that forever changed the relationship. The dogs of today are descendants of and were domesticated from gray wolves.

Greger Larson from the University of Oxford, along with an international team, examined the genomes (genetic makeup) of 27 ancient dog species from remains dating back 800 to11,000 years ago. The team discovered that 11,000 years ago, there were five distinct species of dogs from Northern Europe, the Near East, Siberia, New Guinea, and the Americas. It turned out that today's dog species can trace their ancestry to one of these five ancient species. For example, the chihuahuas are descendants of ancient dogs from the Americas, while the huskies are descendants of the Siberian breed. The team also found that most of the modern European dog breeds come from two breeds - Northern Europe and the Near East. And finally, the five species trace their origin to one ancient species of wolf.

The scientists found remains of dog species in Europe are originally from the Near East. This led them to conclude that humans traveled with their dogs as they migrated from one area to another. These dogs were brought as companions or to act as guard dogs or hunting dogs.

Finally, with dogs and humans living together, the two also developed similar characteristics such as the ability to digest high-starch diets. When two species adapt to an environment in similar ways, it is known as “convergent evolution”.

As you can see, this study is already changing what we know about our favorite companion. We cannot wait to hear what else scientists unearth!

2 . Today, Mars is a frozen desert with a thin atmosphere, too cold for liquid water to remain on the surface. Overwhelming evidence exists that Mars had liquid water oceans roughly 4 billion years ago. The question that drives our interests isn’t whether there’s life on present-day Mars. We are driven instead by asking whether there was life on Mars billions of years ago, which seems significantly more likely.

But if water existed on the Marian surface before, how was it possible? Mars is further away from the sun than Earth, and billions of years ago, the sun didn’t throw off as much heat as it does now.

The planet’s protective magnetic field mysteriously disappeared around 4.2 billion years ago as Mars cooled after forming. The sun’s solar wind then blew away the Martian atmosphere. leaving behind the thin one the planet has today.

Scientists believe the atmosphere was a key component for a warm, wet Mars that may have once hosted life. To have made the planet warm enough for liquid surface water, its atmosphere would likely have needed a large amount of greenhouse gas, carbon dioxide specifically.

Currently, we don’t know the carbon dioxide content of Mars ancient atmosphere. So the researchers turned to the Nordlinger Ries crater（陨石坑）in southern Germany. It was created by a meteorite（陨石）impact 15 million years ago. That geology and the chemistry of the site act as a good similar for the Martian surface.

Researchers will study the pH and nitrogen that might have been in ancient Martian water, which will show the carbon dioxide content in its ancient atmosphere. That will throw light on whether Mars was once warm enough to support life.

The Mars 2020 rover（探测器）will land in a similar crater next year, collecting samples that will be returned to Earth in a future mission. It could be 10 to 20 years before Mars samples are brought back to Earth. We might know the answer to one of the first questions once these samples are distributed to labs in the US and throughout the world.

4 . After traveling more than seven months in space, Tianwen 1 is one step closer to Mars! Tianwen 1, China’s first Mars probe （探测器）, successfully entered Mars orbit in February, according to the China National Space Administration （CNSA）. It will stay in orbit for about three months before landing on the red planet.

A small step on the red planet will be a big step for human beings. Humans have launched 46 Mars exploration missions since October 1960, but only 19 of them have been successful, according to China Daily. It’s China’s first spacecraft to Mars, and the missions are rather ambitious. Tianwen 1 aims to achieve “orbiting, landing, and roving （环绕，着陆，巡视）” all in one journey, which will make the country the world’s first to accomplish all three goals with one probe, mission scientists said. Among the three tasks, touchdown on the red planet is the most difficult. The result mainly depends on the “breathtaking seven minutes,” which will deploy multiple cutting-edge technologies and accurate timing of each action, including the burning of engines and opening of parachutes （降落伞）to ensure a safe landing, according to the Global Times. The previous success of Chang’e 5 has accumulated experience in this regard which “boosts our confidence”, Wang Ya’nan, chief editor of Beijing-based Aerospace Knowledge magazine, told the Global Times. Tianwen Vs ultimate goal is to land a rover on Mars in May or June, and it will conduct scientific investigations on Mars’ soil, geological （地质学的）structure, environment, atmosphere and water, according to China Daily.

February was Mars month. NASA’s Perseverance Rover landed on Mars on Feb 19, and China’s Tianwen 1 and United Arab Emirates’ （UAE） Hope have arrived within orbit of the red planet. Although they started their Mars journeys at almost the same time, their missions vary. “When we step into the far planets of the solar system, the magnitude （量级）of the resources and timeline required will take a global commitment,” US Congressman Frank Lucas said, highlighting the importance of international cooperation in space.

5 . While flatmates can bring about stress and difficulty, they can also be great company and develop into wonderful, lifelong friends. Before making the decision to live with a flatmate or to live alone, consider carefully all the accompanying advantages and disadvantages.

Most people join forces with a flatmate primarily due to financial problem. A shared living space also means you're responsible for only half of the rent or shared bills. Additionally, when you're splitting costs, you can afford a better apartment than you could alone. However, money can become a point of argument for flatmates as well. If your flatmate gets laid off or quits his job, you may have to pick up his bill until he's back on his feet. Your flatmate may also insist he owe less because he doesn't use the shower too often.

In addition to bills and the rent, flatmates also typically share responsibility for unpleasant tasks, such as cleaning or doing the dishes. Without a flatmate, cleaning and tidying responsibilities are yours alone. However, flatmates also frequently end up sharing plenty of other things many people would rather not: use of the TV, the bathroom, food and even clothing, for example. You may have to wake up earlier than you'd like to get a hot shower before work or give up watching your favorite show because your flatmate beat you to it.

When you live alone,   you get to determine the terms of your social life, and you go home to an empty house or apartment at the end of the day. That can be preferable if you're a serious student or professional, someone who needs to work and rest in the quiet of an apartment. With a flatmate, there are unexpected guests and your social options can expand sharply. Keep in mind, however, that having a flatmate means that he may feel social when you do not, and you may have to deal with wanted house guests.

7 . As many areas have encouraged people to stay put during the Spring Festival holiday, it would be a great idea if you could go to the cinema to enjoy a wonderful movie, wearing a mask. Here is a brief lineup of the latest films to share with you.

Detective ChinatownⅢ

Following their adventures in Bangkok and New York in the first two movies, the amateur detective duo portrayed by Wang Baoqiang and Liu Haoran travels to Tokyo as they try to solve a murder mystery, which could earn them a huge bonus.

Hi, Mom!

As the directorial debut of comedy actress Jia Ling, the film reflects on how she misses her late mother Li Huanying, who encouraged Jia to pursue her artistic dreams. Interestingly, she fictionalizes time-travel story to depict her mother’s love story set in 1981.

A Writer's Odyssey

As the latest film directed by Lu Yang, best known for the Brotherhood of Blades franchise, the film is highly anticipated. The fantasy tale centers on a novelist amazed to find that the fictional world under his pen is surprisingly influencing the real world.

The Yin-Yang Master

Adapted from the mobile game Onmyoji, the film centers on the Yin-Yang master Qingming, a genius wizard who lives in a fictional world where monsters and human beings coexist. Most monsters from the trailers appear cute and chubby, making the film more appealing to families.

8 . Some time ago, in my class I was about to fail a student for his answer to a physics question when the student claimed he deserved a better score. The examination question sounded “safe”.

“Show how it is possible to determine the height of a tall building with the aid of a barometer（压表）.” The student had answered: “Take the barometer to the top of the building, attach a long rope to it, lower the barometer to the street, and then bring it up, measuring the length of the rope. The length of the rope is the height of the building.”

I argued that a high grade should prove his competence in physics, but the answer did not confirm this. I suggested that the student have another try. Immediately, he worked out his answer: A second best way is to take the barometer to the top of the building. Drop the barometer, timing its fall with a stopwatch. Then, using the formula to calculate the height of the building.

I was shocked by his answer. His method gave me not only a broken barometer but a U-turn in my teaching philosophy. I gave him full marks.

On his leaving my office, I recalled that he suggested there could be a better answer. So I asked him what it was. “Oh, yes,” said the student, “There are many ways. Probably the best,” he said, “is to take the barometer to the basement and ask the superintendent （楼管）. You speak to him as follows: Mr.Superintendent, here I have a fine barometer. If you tell me the height of this building, I will give it to you.

At this point, I asked the student if he really did not know the conventional answer to this question. He admitted that he did, but said that he was fed up with high school instructors’ trying to teach him how to think, and to use the so-called “scientific method”. He just wanted to solve the problem in a practical manner, not just answer the question in an expected way. Hearing this, I really had nothing to do but give the boy a firm handshake, feeling thankful that I hadn’t failed him in the first place and even more thankful, neither had he.