2 . As we all know, swimming is great fun. But it often comes with ________. Drowning is a real possibility even for the most ________ swimmers. However, this dangerous situation can be changed with watchful eyes. This summer in Florida, two young men helped to ________ one drowning death.

Griffin Emerson, a 6-year-old child, swam in an apartment block’s pool. He enjoyed the pool’s ________ area. But he began to ________ toward the deeper part slowly, struggling to keep his head above water. All that came about as no one else, including his mother, seemed to ________ him. Griffin’s frightening ________ in the water happened over the course of a full minute, ending up with the child going down to the ________ of the pool.

However, one young man, Noah, did find Griffin in the pool. He told his friend Weston to call 911 at once. And Noah ________ to jump into the pool to ________ the 6-year-old. Noah made it to Griffin, caught him and ________ him to the surface and then to the side of the pool. Before the emergency services’ arrival, Noah and Weston tried their best to ________ life-saving steps.

________, a few minutes later, Griffin recovered his breath. Griffin’s mother was ________ to Noah and Weston for their heroic actions. But the two young men thought it was no big deal and hoped that this act of kindness would be ________.

3 . Dogs may understand more than they show. Pet dogs’ brains displayed neural (神经的) signs of surprise when their owners showed them an unexpected toy. The findings, published March 22 in Current Biology, suggest that dogs create mental concepts of objects.

“Anyone who has ever interacted very much with a dog probably is not surprised to know that dogs understand what your speech is referring to, especially when it contains common objects,” says Ellen Lau, a neuroscientist at the University of Maryland in College Park. But some people may assume that this “understanding” is a simple reaction to the sound of the word.

Marianna Boros, a neuroscientist at Lorand University in Budapest, recruited 27 pet dogs and their owners. The team asked the owners to bring five familiar toys and other objects to the lab. Researchers stuck electrodes (电极) to the dogs’ heads and gave them two tasks: lie on the floor and stay awake.

Every so often, a dog would hear a recording of its owner saying things like, “Kun-Kun, look, the ball!” The dog’s owner was on the other side of a wall with a window covered by the curtains. Just after the recording played, the curtains were opened, showing the owner holding a toy — the ball or a different toy, such as a rope.

Just after seeing an unexpected object, an electrode monitoring (监测) brain activity picked up a larger-than-normal signal. This signal indicates surprise, the team says, and suggests that the dog had already formed a mental concept and expectation of the ball after hearing that word. In fact, the signal was especially strong for a mismatch involving words that the dogs knew very well. “That suggests that it is really about understanding and knowledge of the word,” Boros says.

4 . Are aliens trying to contact Earth? Six new mysterious blasts (爆炸) of radio energy are detected from deep space. While the source of the waves remains unknown, some suggest the mysterious bursts of energy could be a sign of alien life trying to contact us. The waves were detected by researchers from McGill University in Montreal.

The detection follows 11 previously recorded outbursts from the same location, called FRB121102. This is the only known repeater of fast radio bursts (FRBs). Despite there being a number of FRBs from the site, the origin of the bursts is an ongoing puzzle to researchers.

But the researchers say that the repeated outbursts imply that whatever is causing the radio bursts is not a one-time event, such as an explosion or collision. Instead, they say that flares (耀斑) from a young neutron star (中子星) are a promising candidate.

Previously when waves have been detected, astronomers have also asked SETI (Search for Extraterrestrial Intelligence) to take a closer look at whether they could be a message from aliens. But it is unclear whether the McGill researchers will ask SETI to help this time.

If there are any intelligent alien life forms out there, Stephen Hawking thinks we’re playing a dangerous game by trying to contact them. The physicist believes if aliens discovered Earth, they would likely want to conquer and colonize our planet.

”If aliens visit us, the outcome could be much like when Columbus landed in America, which didn’t turn out well for the Native Americans, “he said in an interview.

But co-founder and former director of the SETI Institute, Jill Tarter, doesn’t think this will be the case. She argues any aliens who have managed to travel across the universe may be friendly and peaceful.

“The idea of a civilization which has managed to survive far longer than we have... and the fact that the technology remains an aggressive one, to me, doesn’t make sense,” she said.

5 . Richard Browning has been attracted by flight ever since his father took him into the hills to fly gliders (滑翔机). He has certainly been an adventurer. Richard took it upon himself to develop his own jet suit and began to experiment with some of his friends. He made quick progress. In 2017, he felt confident enough to start a company called Gravity Industries that could make jet suits. It took 15 months to develop the very first one.

Five very small jet engines are built into the jet suit. These are powered by kerosene (煤油). Two engines are located on the pilot’s arms and one is placed on the back. Each engine weighs less than two kilos and can produce 22 kilos of thrust (推力).

The pilot is able to control the direction and speed of the flight. He does this by small movements of the arms which require hours of practice. One wrong move and you could end up falling to the ground.

Richard is not only in charge of his company; he is also the chief test pilot. He has spent hours and hours perfecting the correct moves to create a perfect flight. He was able to enter the Guinness Book of World Records in 2017 when he became the fastest man in a jet suit and flew at 51 kilometres per hour. Since then, he has presented his jet suit at 60 events in 20 different countries around the world. More recently, he flew alongside Brighton Pier on the south coast of England at 136 kilometres per hour!

The objective of Richard’s company has been to build a suit which members of the public can buy. The first went on sale in a department store in 2018 for f 340, 000. If you want to jet around your own hometown, it’s time to start saving—or to work for Richard Browning.

6 . Sadie looked out of the window and sighed (叹气) as she thought about another long, boring day of summer. She wondered what all of her friends from school were doing on their summer vacations. It had to be a lot better than looking out of a window. Sadie thought about the fun she had last summer when she and her best friend Allison went to the beach. They built sandcastles, played beach volleyball, and even tried surfing. But they wouldn’t be going to the beach together this summer because Allison had moved to a different city far away from Sadie’s.

Suddenly, Sadie had an idea. She could call her friend Wendy, who always had funny ideas. Maybe they could ride their bikes together around the park. Sadie raced to the living room, picked up the phone, and called Wendy. She sighed more deeply as the phone rang and rang. Then Sadie seated herself on the sofa, picked up the television remote, and put it down again. She didn’t really want to watch television, so she went to her room and found the list of phone numbers of her good friends from school. In the living room, she called almost each of them, but no one was at home.

After hanging up the phone, Sadie wandered into the kitchen and sat down at the table, watching her mom do the cleaning. “Mom, I don’t have anyone to hang out with because my friends from school aren’t home and Allison moved away,” said Sadie. “Honey, there are many things you can do by yourself, like playing your guitar or having a walk in the garden. You could even finish that story about our camping trip,” said Mom.

“I don’t want to do those things by myself. I want to play with a friend.” “Sometimes, it is nice to do things by yourself,” said Mom. “I like seeing my friends, but I also like doing things alone like taking a walk by myself or finding a quiet spot to read. Why not have a try?”

Sadie thought about her mom’s words and returned to her room.