You probably know who Marie Curie was, but you may not have heard of Rachel Carson. Of the outstanding ladies listed below，who do you think was the most important woman of the past 100 years?

Jane Addams (1860－1935)

    Anyone who has ever been helped by a social worker has Jane Addams to thank. Addams helped the poor and worked for peace. She encouraged a sense of community (社区) by creating shelters and promoting education and services for people in need. In 1931，Addams became the first American woman to win the Nobel Peace Prize.

Rachel Carson (1907－1964)

    If it weren't for Rachel Carson, the environmental movement might not exist today. Her popular 1962 book SilentSpring raised awareness of the danger of pollution and the harmful effects of chemicals on humans and on the world's lakes and oceans.

Sandra Day O'Connor (1930－present)

    When Sandra Day O'Connor finished third in her class at Stanford Law School, in 1952, she could not find work at a law firm because she was a woman. She became an Arizona state senator (参议员) and，in 1981, the first woman to join the U．S. Supreme Court. O'Connor gave the deciding vote in many important cases during her 24 years on the top court.

Rosa Parks (1913－2005)

    On December 1, 1955, in Montgomery, Alabama, Rosa Parks would not give up her seat on a bus to a white passenger. Her simple act landed Parks in prison. But it also set off the Montgomery bus boycott. It lasted for more than a year, and kicked off the civil ­ rights movement. “The only tired I was, was tired of giving in，”said Parks.

    It is commonly believed that the earliest Chinese paper-cuts appeared during the sixth century. Some scholars believe it was even earlier. Legend has it that during the Western Han Dynasty(206BC-AD24), Emperor Wudi was very sad after one of his favorite concubines, Madame Li, died. A Taoist priest, Li Shaoweng, cut a piece of hemp paper in the shape of Madame Li. When evening fell, the emperor's servants lit candles in his bedroom; the reflection of that paper-cut on the wall made the emperor think about his beloved concubine.

    The Yuxian paper-cut is different from most paper-cuts produced in other regions of China. Paper-cuts from other regions are mostly cut with scissors or knives from single-colored paper, such as red or black paper.

    There are four major procedures to making the Yuxian paper-cut: First, sketch the pattern on the draft paper; second, fasten the draft to the paper to be cut; third, use a knife to carve out the pattern; and fourth, dye (染色) the paper-cut with various colors.

    Precise cutting skills are needed to make a piece of the Yuxian paper-cut, which highlights the craft maker's artistic taste and dyeing skills. That explains the following saying: "The successful making of a Yuxian paper-cut is 30 percent dependent on the maker's cutting skills, and 70 percent on the maker's dyeing skills."

    The traditional Yuxian paper-cut highlights two themes: flowers and characters in Chinese operas. The paper-cut is particularly known for its vivid description of characters in various traditional Chinese operas. In October 2009, the art of Yuxian's paper-cut was added to the list of Intangible Cultural Heritage (非物质文化遗产) established by UNESCO (United Nations Educational, Scientific, and Cultural Organization).

    Pangolins (穿山甲) are strange-looking creatures, covered with hard scales (鳞). They can roll up into a ball to protect themselves from enemies and have tongues that are longer than their bodies.

    Pangolins have recently become the focus of Chinese people. A screenshot (截屏) of a micro blog post showing some people eating pangolins at a feast spread. A few days later, people were angered again by pictures showing people eating protected animals, including pangolins.

    Yet this is only the tip of the iceberg. Many more pangolins have been hunted or killed. According to the International Union for Conservation of Nature (IUCN), more than 1 million of them have been killed or sold in the last 10 years. It also said that they are the most illegally traded mammals in the world. In September 2016, the IUCN added the pangolin to the world's "endangered animals list". They are now more endangered than pandas.

    A growing trade of their scales and meat is the main reason for their decline in numbers. Many people in Asia and Africa consider pangolin meat is delicious. Some people even think pangolin scales have medical qualities. However, their scales are made of keratin (角蛋白), the same material human fingernails are made of.

    Luckily, the situation is getting better. World Pangolin Day is on the third Saturday of February each year. It's a day to help people know more about pangolins. The government now stops anyone from buying and eating pangolins in China. Breaking this law is regarded as a crime. The trade of pangolins across the world is also not allowed, according to the Convention on Trade in Endangered Species of Wild Fauna and Flora.

    Black Friday

    The day after Thanksgiving is the start of the holiday shopping season. Thanksgiving is always on a Thursday, so the day after is a Friday. This day has come to be known as Black Friday. It has been the busiest shopping day of the year since 2005.

    Most stores offer great deals on Black Friday. They open their doors in the small hours of the morning. They try to attract shoppers with big discounts. Some items like TVs are much cheaper than usual. Stores may even lose money on these items. They hope that shoppers will buy gifts for other people while they are in the store.

    Black Friday is a great time to get good deals. The problem is that there are not enough low-priced items to go around. Each store may only have a few. These items are in high demand. People stand in long lines to get such great deals. They may line up hours before a store opens. They may be hoping to get a low price on a TV or laptop, but not everyone who wants one will get one. Some people leave disappointed.

    The situation can be tense(紧张的). Some Black Friday events have been violent. Large, eager crowds have trampled(践踏) workers. Fights have broken out over toys or people cutting in line. People have shot one another over parking spots. But most Black Friday events are safe and fun. Still, if you plan on going, expect large crowds and a bit of pushing and shoving.

    So where does the name "Black Friday" come from? It was first used in Philadelphia in the 1950s. The police called this day Black Friday because of the heavy traffic it drew. In the 1960s, spread across the country. It seems that it is here to stay.

    Now people all over the country take part in the event known as Black Friday. It is even spreading to other parts of the world. Stores have held Black Friday events in the U.K., Australia, and Brazil since 2012. In Costa Rica Black Friday is known as "Viernes Negro." And in Mexico, stores offer an annual weekend of discounts. They call it "El Buen Fin," which means "the good weekend" in Spanish. I guess the language of savings is universal.

    Everyone knows that if a dog's ears are up and its tail is wagging vigorously, it is definitely pleased to see you, but now scientists using a robot have found that the way dogs use their tails is more complicated than we thought, and that dogs which wag them to the left may he more friendly. The animal psychologists discovered that when real dogs approached a life-sized robot dog, they were less cautious about it when it was wagging its tail to the left, while if it was wagging its tail to the right, far fewer dogs approached it in a confident manner.

    In the first experiments, 56 percent of the animals approached the model without hesitation when the tail was wagged to the left, while only 21 percent did so in the other situation. When the researchers excluded (排除) owners from being present, the result were: 31 percent of the dogs approached continuously when the tail was wagging to the left, while only 18 percent did so when it was on the right.

    Animal psychologist Roger Mugford said it added to the growing evidence that does were even more complicated communicators than the animals more closely related to man such as monkeys. He said, "We know that dogs, in a sense, have languages, but it is more complicated because it is not just them wagging their tails, but also giving out chemical displays."

    He adds, "The research confirms earlier studies suggesting that dogs, like humans, had a left-side preference. If you are going to present a signal to a dog, it is sensible to put it on your left-hand side because that is where dogs, unlike most other animals, tend to look. It is another example of the similarity between dogs and humans. They are a lot more human than we give them credit for."

    Do you like to show off your expensive items? You could find yourself without friends! Scientists prove that expensive status symbols make you look less socially attractive.

    Items such as a fancy car and a Rolex watch are often thought to increase our social standing(地位) and often come with a high price tag(标签).According to the latest research, however, it has the opposite effect and people would prefer to be friends with someone who places less value on material objects.

    "Often we think that status symbols will make us look more socially attractive to others," says Stephen Garcia, the study's leading author from the University of Michigan. He adds, "However, our research suggests that these status signals actually make us look less socially attractive.

    The researchers conducted six studies which assessed how people presented themselves and how people viewed strangers. People who chose to wear higher status items tended to get a negative response, but people wanted to be friends with people who preferred lower status symbols.

    The study took the role of the luxury(奢侈) item to see if it was possible that the expensive item itself played a part in people's reactions. The definition of a status symbol changed based on a person's socioeconomic status, but the same effect of keeping off potential friends was seen regardless of social position.

    "At a social level, we may be wasting billions of dollars on expensive status symbols that finally keep others from wanting to associate with us, "says Kimberlee Weaver Livnat at the University of Haifa. She says, "And to the extent that close friendships are important to well-being, and we may be unintentionally hurting ourselves."

    However, Patricia Chen of the National University of Singapore said this does not necessarily mean status symbols are a bad thing. She says, "Our findings right now only apply to the formation of new friendships. Status symbols may be beneficial at other times and in other settings, such as when trying to establish new business contacts."