Some unwelcome visitors from North America have been turning up in the waters off the coast of Great Britain.

    North American lobsters (龙虾) have been found in the North Sea (between Great Britain and Northwest Europe), far from their own habitat. The lobsters usually live along the eastern coast of Canada and the United States.

    It is impossible that the lobsters could have made the 5,600-kilometre journey on their own. They were probably brought to Britain and then got away from containers. Some of the lobsters that were caught had elastic bands (松紧带) holding their legs shut, like lobsters that are kept in containers in stores or restaurants.

    Many may have been “set free” from some ships passing through the area. Sometimes passengers order a live lobster from a tank in the dining room and then ask the waiter to throw it overboard instead of cooking it.

    According to official records, 26 North American lobsters have been caught in waters off Great Britain since 1988. However, it is believed many more have been found but not reported.

    It is against the law to let North American lobsters come into British waters. If they settle down in European waters, it would be bad for the local lobsters. The two live in the same place and eat the same food. But North American lobsters are larger, stronger and more aggressive (好斗的) than European lobsters, and they produce young more quickly.

    As a result, they could take food and space away from the local lobsters, and from other types of shellfish that live in the same area. These lobsters may also carry diseases that could harm the local lobsters.

    It was dawn of March 21, 2018. Gary Messina was on his morning run along New York City'8East River. Suddenly something caught his eye—a large 60-year-old man balancing on the four-foot-high fence that guarded the path from the water. As Messina got closer to the scene, the man took a step forward and slipped into the dark river below.

    When Messina reached nearer, the man was struggling in the water, clearly unable to swim. Other joggers also heard the man's cry. David Blauzvern and John Green dropped their phones and keys on land and jumped in. “ People had called the police, but it was unclear when they'd get there,” says Green. “We just reacted. Messina joined them in the river. Just as the jumper was losing strength, Blauzvern take hold of him. The pair were about 30 yards from the seawall when Messina and Green caught up to them. They seized the man, with Blauzvern supporting his back and Messina and Green holding him up from either side. As the men made their way toward the concrete seawall that stretched for blocks in each direction, Blauzvern had an awful realization:there was no way out of the river.

    By now, a crowd had gathered on land. “A rescue boat is on its way, someone yelled to them. Swimming forward was getting tougher by the minute. The jumper, who was six foot two and weighed around 260 pounds, was heavy in his rescuers' arms. After ten minutes, they managed to get to the river's edge. “I've never been so out of breath, ”says Blauzvern.

    Fifteen minutes after the men had jumped into the river, the two-man rescue boat appeared. But because it couldn't risk getting too close to the seawall, the men had to swim out to it. “I was completely out of energy at this point, “says Blauzver. The men in the water pushed the jumper while the men in the boat pulled him up and, finally, to safety. The man they had saved was taken to the hospital for evaluation(评估). Details on his condition have not been released. As for the rescuers, each of them was at work by 10:30a. m. “I was a bit late,” admits Blauzvern, smiling. “But I had a good excuse.”

    T-shirts out; uniforms in

    School uniforms are becoming more and more popular across the U.S.A. That's no surprise, because they offer many benefits. They immediately end the powerful social sorting and labeling (标记) that come from clothing. If all students are dressed in the same way, they will not pay too much attention to their clothing, and some of them will not be laughed at for wearing the “wrong” clothes.

    Some people are against the strict rule of school uniforms, but they do not realize that students already accept a kind of rule — wanting to look just like their friends. The difference is that the clothing students choose for themselves creates social barriers; school uniforms tear those barriers down.

    As in other places, uniforms remind the wearers of their purposes and duties. For example, when a man or woman puts on a police uniform, he or she becomes, for a time, the symbol of law and order. The uniform means to the wearer his or her special duties and sends the same message to everyone the wearer meets. People with different jobs wear uniforms of one kind or another. For students, the school uniform reminds them that their task for the six or seven hours they are in school is to get an education.

    Some parents are unhappy about uniforms, saying that school uniforms will affect their children's “creativity.” First, the clothes students choose to wear do not necessarily express the individuality. They just copy their classmates. Second, students have the rest of the day to be as creative as they like. While they're in school, their job is to master reading, writing, and math; this should take up all the creativity they have. Mastery of those skills will be good for the students to build up their creativity in every way.

    How does a sunset work? We love to look at one, but Jolanda Blackwell wanted her eighth-graders to really think about it and question.

    So Blackwell had her students watch a video of a sunset as part of a physics lesson on motion. "I asked them: ' So what's moving And why' " Blackwell says. Some thought the sun was moving; others knew that a sunset is the result of the Earth spinning around on its axis. "Usually, my biggest challenge is trying to keep them patient," she says. "They just have so many burning questions."

    "Every day, we meet new information," says Charan Ranganath, a psychologist. Ranganath was curious to know why we keep some information and forget other things. So he got 19 volunteers and asked them to review more than 100 questions. When the participants' curiosity was aroused, the parts of' their brains that regulate pleasure and reward lit up. Curious minds also showed increased activity in the brain, which is involved in greater memories.

    "Curious brains are better at learning not only about the subject at hand but also dull information. This is a phenomenon teachers can use in the classroom," says Evie Malaia, a professor. "Say a kid wants to be an astronaut," she says. NL Well, how do you link that goal with learning multiplication tables(乘法表)" "A teacher may choose to ask her class an interesting word problem that involves space exploration," Malaia says. Students may remember the answer to the word problem, but they'll also remember how they found the answer through multiplication.

    What Ranganath wants to know most is why some people seem naturally more curious than others. Lots of factors, including stress, aging and certain drugs  affect dopamine(多巴胺) processing in the brain. "If we could figure these things out, we could help those who may just seem bored," Ranganath says.

    Blackwell says she doesn't have to deal with that problem too often. She says her students love exploring the mysterious unknowns in science: What happens when a car crashes. How do rainbows work "I tell my kids there's no dumb questions," Blackwell says. "That's science: asking questions and seeking answers."

    Once there was an 11-year-old boy who went fishing with his father in the middle of the Finger lake. On the day before salmon(鲑鱼) season opened, they were fishing early in the evening, catching other fish with worms. Then the boy tied on a small silver lure (鱼饵) and put it into the lake. Suddenly he felt that something very big pulling on the lure. His father watched with admiration as the boy skillfully brought the fish beside the bank. Finally he lifted the tired fish from the water. It was the largest one he had ever seen, but it was a salmon.

    The boy and his father looked at the big fish. The father lit a match and looked at his watch. It was 10 pm – two hours before the season opened. He looked at the fish, then at the boy. “You'll have to put it back, son,” he said.

    “Dad!” cried the boy, “There will be other fish,” said his father. “Not as big as this one,” cried the boy. He looked around the lake. No other fishermen or boats were in sight in the moonlight. He looked again at his father.

    Even though no one had seen them, nor could anyone ever know what time he had caught the fish, the boy could tell from his father's voice that the decision couldn't be changed. He threw the huge salmon into the dark water. The big fish disappeared. The boy thought that he would never again see such a big fish.

    That was 34 years ago. Today the boy is an successful architect in New York City. He often takes his own son and daughters to fish at the same place.

    And he was right. He has never again caught such a large fish as the one he got that night long ago. But he does see that same fish … again and again … every time he has an ethical (伦理的，道德的) decision to make. For, as his father had taught him, ethics are simple matters of right and wrong. It is only the practice of ethics that is difficult.

    According to a recent study, a new genetically modified rice can prevent infections of HIV, the virus responsible for the disease AIDS.

    The study reports the newly-developed rice produces proteins that attach directly to the HIV virus. This process prevents the virus from mixing with human cells. The scientists say it can remove the effect of the virus and block its spreading.

    The Joint United Nations Program on HIV/AIDS reports that worldwide, nearly 37 million people were living with HIV in 2017. The organization says the largest number of those are in developing countries. Nearly two-thirds of HIV cases are in Africa. Now there is no cure for HIV/AIDS though there have been developments in oral drug treatments to slow the progression of the disease.

    The new study predicts the rice-based method will lead to long-term use of the anti-HIV treatment across the developing world. Researchers said the "groundbreaking" discovery is "realistically the only way" that anti-HIV combination treatments can be produced at a cost low enough for the developing world.

    They say the easiest and most cost-effective way to use the rice will be to make it into a cream to be put on the skin. The HIV-fighting proteins can then enter the body through the skin. People all over the world could grow the rice and make the cream themselves. This would prevent the cost and travel required for many patients to receive treatments and medicine.

    The process of changing the genetic structure of food crops has been debated for some time. Critics of genetically engineered crops believe they can harm people. The scientific team says further testing is needed to ensure that the genetic engineering process does not produce any additional chemicals that could be dangerous to people.