No one is sure how the ancient Egyptians built the pyramids near Cairo. But a new study suggests they used a little rock‘n'roll. Long-ago builders could have attached wooden pole s to the stones and rolled then across the sand, the scientists say.

     “Technically, I think what they're proposing is possible,” physicist Daniel Bonn said.

    People have long puzzled over how the Egyptians moved such huge rocks. And there's no obvious answer. On average, each of the two million big stones weighed about as much as a large pickup truck. The Egyptians somehow moved the stone blocks to the pyramid site from about one kilometer away.

    The most popular view is that Egyptian workers slid the blocks along smooth paths. Many scientists suspect workers first would have put the blocks on sleds(滑板). Then they would have dragged them along paths. To make the work easier, workers may have lubricated the paths either with wet clay or with the fat from cattle. Bonn has now tested this idea by building small sleds and dragging heavy objects over sand.

    Evidence from the sand supports this idea. Researchers found small amounts of fat, as well as a large amount of stone and the remains of paths.

    However, physicist Joseph West thinks there might have been a simpler way , who led the new study . West said , “I was inspired while watching a television program showing how sleds might have helped with pyramid construction . I thought , ‘Why don't they just try rolling the things?'“A square could be turned into a rough sort of wheel by attaching wooden poles to its sides , he realized . That , he notes , should make a block of stone” a lot easier to roll than a square”.

    So he tried it.

    He and his students tied some poles to each of four sides of a 30-kilogram stone block. That action turned the block into somewhat a wheel. Then they placed the block on the ground.

    They wrapped one end of a rope around the block and pulled. The researchers found they could easily roll the block along different kinds of paths. They calculated that rolling the block required about as much force as moving it along a slippery(滑的)path.

    West hasn't tested his idea on larger blocks, but he thinks rolling has clear advantages over sliding. At least, workers wouldn't have needed to carry cattle fat or water to smooth the paths.

    There are two great trends on parents bringing up children today．First，children are now praised to an unbelievable degree．As Dorothy Parker once joked，American children aren't raised；they are motivated．Children are constantly told how special they are．The second is that children are honed(磨砺) to an unimaginable degree．Parents spend much more time than in past generations on their children's development．

    These two great trends—greater praise and greater honing—combine in close ways. Parents shower their kids with affection，but it is intermingled with the desire to help their children achieve success．Parents are happy when their child studies hard，practices hard，wins first place，gets into a famous college．

The wolf of conditional love is hidden in these homes．The parents feel they love their children in all circumstances．But the children often think differently．They feel that childhood is a performance—on the athletic field，in school and beyond．The shadowy presence of conditional love produces a fear，the fear that there is no completely safe love．

    Meanwhile，children who are uncertain of their parents' love develop a great hunger for it. This conditional love is1ike an acid that affects children's criteria to make their own decisions about their own colleges，majors and careers．At key decision-points，they unconsciously imagine how their parents will react．

    These children tell their parents those things that will bring praise and hide the parts of their lives that won't. Studies suggest that children who receive conditional love often do better in the short run．They can be model students．But they suffer in the long run. They come to hate their parents．They are so influenced by fear that they become afraid of risk．

    Parents today are less likely to demand obedience(顺从) with explicit rules and lectures．But they are more likely to use love as a tool to exercise control. But parental love is supposed to ignore achievement. It's meant to be an unconditional support -a gift that can not be bought and cannot be earned．

    How did the sea horse get its name? It's not hard to guess. The top half of this fish looks like a small horse. But looking at the sea horse's tail, you might think "sea monkey" is a better name. Then there's the sea horse's pouch(袋). "Sea kangaroo" might also be a good name for this fish.

    Sea horses live in warm ocean waters all over the world. They keep safe from other fish by hiding in plants and grasses that grow under the sea. They can also change colors to match their surroundings(环境). A sea horse remains in one place for hours at a time by winding(缠绕)its tail around a plant. It feeds on live food, such as small shrimp. For a fish that doesn't move around much, the sea horse eats a lot--in just one day, a sea horse can eat 3,000 shrimp!

    A sea horse keeps the same mate for its whole life, and it's the male(雄的)sea horse that gives birth to baby sea horses. How does this happen? Baby sea horses start out as eggs, which come from the female's body. The male carries the eggs in its pouch for about three weeks until they hatch(孵化). Soon after the babies are born, the female gives her mate a new set of eggs. The male sea horse spends most of its life carrying eggs.

    Sadly, the number of sea horses is becoming smaller. Why is this happening? Some places where sea horses once lived have been filled in to make new land. Also, many sea horses are caught and sold as aquarium（水族馆，养鱼缸）fish. This really is not a good idea because most sea horses don't live long in aquariums. The best place for a sea horse is the ocean.

For most people having things stolen feels like an offence. Robbie Pruitt admitted that he got1 when he discovered the theft of his mountain bike last September. But soon enough, his2 took a turn.

After letting go of his anger and frustration, he found himself on a road to sympathy3 .

For Pruitt, a keen bicyclist, the first thing to do was4 his stolen bike. But when he went bike shopping, he found few available, which got him thinking: What if the5 of bikes was Covid-19 related, and what if the person who'd taken his bike really needed6 to get to work?

With that thought in mind, Pruitt7 a plan and posted it on the community website. He8 to repair bikes free of charge for anyone who needed it. He also asked for unwanted bikes, which he would repair—again9 . And then he would donate them to folks who could truly use them but didn't have the 10 to buy one.

The day the post went live, Pruitt received thirty11 bicycles. Then came more than 50012 for detailed information. By the end of 2022, Pruitt had repaired more than 140 for donation or to be13 to their owners.

Pruitt tries to give his donations to families that are14 struggling. Upon satisfying a material need, he has provided an opportunity for kids in his neighborhood to learn how to15 their own bikes.

In addition to16 skills, Pruitt's lessons teach teamwork, encourage self-worth, and promote feelings of community.17 , the kids have gained a sense of accomplishment.

"It's a really great18 for kids," said a neighbor in an interview with the local newspaper. "Pruitt is certainly providing a19 , but it's not just the bikes. It's the relationships in the community. It's the20 he can make on people."

Tonya, Elsa and Mark are students at SAR Senior High School in New York City. It's a school with regular academic(学术的)classes, but it also gives special attention to the performing arts. Tonya likes dancing, Elsa wants to be an artist and Mark is a singer. 

The students are all 15,and they're in the 10th grade. They study subjects like English, maths, and science. They also choose a foreign language. Students have many academic classes, but during the school day they also take classes in the arts, like dance and music. 

There are even more activities for SAR students after school. There are more than 40 clubs for students. For example, there's a movie club, a music club and an environmental club. "We have so many choices to select," says Tonya. "I like taking photos. It's a so a great way to meet people with common interests. "

Students at SAR can also do many sports. For example, they can play basketball, tennis, volleyball and soccer. Students practice them after school. They compete against other high schools. Mark says, "At school, I study by myself. I'm a singer, and I do that alone, too. That's why I like playing on the basketball team. We work together and compete against other teams. "

SAR offers various great classes, clubs and sports to students. Students at SAR get a good education and they also develop their own interests. Many SAR students become dancers, singers and actors!

Cruz Genet,11, and Anthony Skopick, 10, couldn't agree. Were the birds out on the ice ducks or geese? So on a 1 January evening last year, the two friends ventured onto the 2 pond near their homes, to get a better look. First they tossed a rock onto the ice to3 it. Then they stepped on it. 4 the ice would hold their weight, Anthony took a few steps, then…FOOMP. He crashed through the 5 frozen surface." There was no sound, no crack," he recalled,"I just fell through instantly". Cruz 6 to help his panicked friend. FOOMP— the pond 7 him too.

 The boys were up to their necks in icy water and quickly losing feeling in their limbs. Any chance of their 8 themselves was slipping away. Cruz was sure he was going to die. Anthony's older sister was nearby and started screaming for help.

 John Lavin, a9 driving nearby on his way home, heard her. He quickly 10 . Seeing the boys, he grabbed a nearby buoy (救生圈), 11 off his shoes, and ran into the cold water, chopping(劈) his way through the ice with his free 12 .

 Lavin made his way to Cruz and Anthony and pulled them back to land. When in hospital, doctors discovered that their five- minute 13 in the water had lowered their body 14 nearly ten degrees.

 Fortunately, the boys have fully recovered, though they are still a little awestruck by their 15 neighbor." Just to think," says Cruz," If he weren't there, we could have died."