Work started this week on next season's flu vaccine (疫苗), with experts working off forecasts about which types of the flu virus will be making the rounds. But don't expect any improvements. Flu experts are already admitting that most vaccines will give at best basic protection, because they're based on old-fashioned technology. It's not a new problem, but one that the slow-moving world of drug and vaccine production seems helpless to improve upon.

    Every flu vaccine is a cocktail, aimed at either three or four of the most common flu types. Flu vaccines must be recreated every year because flu viruses develop constantly in a process called antigenic drift. In February, global flu experts gather to trade notes on what viruses are circulating in different countries and to come to an agreement on which types the next vaccines should be made to target.

    In recent years, flu vaccines have been based on H1N1, H3N2 and either one or two types of influenza B virus. Each of these has a "reference" type, which is used to make seed virus. Producers add the seed types to eggs and incubate (孵) them as the virus grows. Then they purify the virus, and either weaken it or kill it to make a vaccine.

    Using eggs is a tricky (=difficult) and unpredictable process. Sometimes the virus doesn't grow well in eggs, which can mean less vaccine than expected. The result is a flu vaccine that doesn't offer much protection. "As long as we have eggs we are going to have this problem," said Scott Hensley, a flu virus expert, "The only solution is not to depend on eggs."

    Flu is a major killer. The 2017-2018 season has been a severe one, hitting the entire U. S. with widespread influenza infection (感染) at once for weeks on end, and killing 97 children so far. Against this threat, even a less satisfying flu vaccine will definitely help. "Even when you have these mismatches it will not prevent infection but likely prevent disease severity," said Hensley.

    Last year, three experienced storm chasers were killed in a tornado(龙卷风)in the US, but despite this the number of people going in search of tornadoes is growing. What drives them to take risks and look for danger? The man at the wheel glanced in the back-view mirror and then slowly turned around. "Don't put this in your program." he said. His wife in the passenger seat laughed. He lowered the window and killed the engine. The wind rushed in from surrounding wheat fields.

    Then, from behind, the sound of footsteps approached on the dirt road. It was a moment of peace after hours of speedy racing through the American grassland. There had been excited shouts about where a tornado might form and how we would be there if it did. We were crazy on the trail a moment ago. But now, everyone was very cool. A Kansas state trooper(骑警) introduced himself through the window. There was pretended surprise when he said how fast we had been going. Really? Wow, sorry.

    Val Cator handed over his driver's license. His wife, Amy, took the registration out of the glove box. Val explained they were storm chasers with Channel 9 News out of Oklahoma City—though it was hardly necessary. Their huge black truck has lightning bolts(闪电)and Storm Tracker 9 painted on the sides.

    Val pointed to the radar on the laptop open next to him and said those red and green dots suggested a tornado could form this afternoon. The state trooper was untouched. "I've got that in my car too." he said. People here keep a close eye on the weather. It's part of living in the tornado alley. Every year some town or other is blown off the map by tornadoes that can reach 300 miles an hour.

    Val and Amy are just two of hundreds of possibly thousands of trackers who speed around with computers and cameras hoping to catch one of these beautiful, deadly storms. I'd joined them to learn why the number of trackers keeps growing. Why are people taking real risks—beyond the steady diet of rest-stop junk food—to watch weather?

    Last year, a tornado killed three of the most experienced storm chasers. It picked up and threw their car as easily as you would a piece of paper. Dozens of other chasers were hurt in the same storm. They were crowded on a few roads when the tornado suddenly expanded and ate them. Val and Amy were there that day but still, in their words, chase aggressively.

    A child who suffers bullying(霸凌) usually has low self-esteem and their ability to learn and be successful at school is greatly lessened. Therefore, bullying must be stopped.

    The best and most obvious way to stop bullying in schools is for parents to change the way they raise their children at home. Of course, this is much easier said than done and everyone raises their children differently. Bullies, however, come from homes where physical punishment is used and children have been taught that physical violence is the way to handle problems and “get their way”. Bullies usually also come from homes where the parents fight a lot, so children have been modeled on such violence. Parental involvement is often lacking in bullies' lives and there seems to be little warmth.

    Early intervention (干预) is truly the best way to stop bullying, but parents of the victims or therapists(治疗师) can't alter the bully's home environment. Some things can be done at the school level, however. Most school programs that address bullying apply a multi-faceted(多层面的) method to the problem.

    Hand out questionnaires to all students and teachers and discuss if bullying is occurring. Define exactly what constitutes(构成) bullying at school. The questionnaire is a wonderful tool that allows the school to see how widespread bullying is and what forms it is taking. It is a good way to start to solve the problem.

    Get the children's parents involved in a bullying program. If parents of the bullies and the victims are not aware of what is going on at school, then the whole bullying program will not be effective. Stopping bullying in school takes teamwork and concentrated effort on everyone's part. Bullying also should be discussed during parent-teacher conferences and PTA meetings. Parental awareness is the key.

    In the classroom setting, all teachers should work with the students on bullying. Oftentimes even the teacher is being bullied in the classroom and a program should be set up to teach about bullying. Children understand modeling behaviors and role-play and acting out bullying situations is a very effective tool. Have students role-play a bullying situation.

    It is easier to float in the ocean than it is to float in a swimming pool. Do you know why?

    Ocean water is full of salt— and salt water can hold up more weight than fresh water. See for yourself!

    You Will Need:

    3 cups of warm water

    Measuring cup (量杯)

    Wide-mouthed jar

    Salt

    Spoon

    Raw (生的)potato

    You Will Do:

    ⒈Pour 1.5 cups of warm water into the jar.

    ⒉Add 1/3 cup of salt.

    ⒊Stir(搅拌) until the salt is completely dissolved.

    ⒋Add another 1.5 cups of water. Pour it slowly over the back of the spoon into the jar so that the two liquids will not mix together.

    ⒌Gently place the potato into the jar. Do not drop it.

    What Will Happen:

    The potato will sink— but only halfway!

    Why?

    Salt water is heavier than fresh water, so it will stay on the bottom. The fresh water will remain on top.

    The potato is heavier than the fresh water, but it is lighter than the salt water. That is why the potato will sink halfway down.

    English is the most widely used language in the history of our planet. One in every seven human beings can speak it. More than half of the world's books and three quarters of international mail are in English. Of all languages, English has the largest vocabulary — perhaps as many as two million words.

    However, let's face it: English is a crazy language. There is no egg in an eggplant, neither pine nor apple in a pineapple and no ham in a hamburger. Sweet-meats are candy, while sweetbreads, which aren't sweet, are meat.

    We take English for granted. But when we explore its paradoxes (探讨它的矛盾), we find that quicksand can work slowly, boxing rings are square, public bathrooms have no baths in them.

    And why is it that a writer writes, but fingers don't fing, grocers don't groce, and hammers don't ham? If the plural of tooth is teeth, shouldn't the plural of booth be beeth? One goose, two geese — so one moose, two meese?

    How can a slim chance and a fat chance be the same, while a wise man and a wise guy are opposites? How can overlook and oversee be opposites, while quite a lot and quite a few are alike? How can the weather be hot as hell one day and cold as hell the next?

    English was invented by people, not computers, and it reflects (反映) the creativity of human beings. That's why, when stars are out, they are visible (能看见的); but when the lights are out, they are invisible. And why, when I wind up my watch, I start it; but when I wind up this essay, I end it.

    One night I received a Facebook message from Laura, a former classmate. "Hey Steve," she said, "I know you've always been an animal lover. I've just had a baby and I can't keep my mini pig."

    Being fond of animals, I knew I wanted the pig. I just had to figure out how to make it happen. I lived in a two-bedroom single-level house in Georgetwon, Ontario. It's tough to bring a pig back to the house I share with two dogs, two cats, and my lifelong partner.

    But I was not letting that pig go. So I told Laura I'd take the animal. When I got home with the pig, I hid her in the bedroom, and began to prepare a dinner for Alisha—her favourite bacon cheeseburgers. It's better to make her happy before introducing the new member to her.

    When I led her to the bedroom and showed her the surprise, Alisha stood in the doorway like a statue. It took her a few seconds to know what I had done. She complained about my unreasonable action. She insisted there was no more room in the house.

    I knew I was wrong, but I hoped I could smooth things over. Soon enough, the lovely pig did the smoothing for me. Never had we felt such joy as she brought to us. We got her a name "Esther".

    Esther's arrival changed our lives. A few weeks later, we decided to stop eating bacon. We figured it was our turn to try to change the world for other animals. A few months later, we moved to a farm where we cared for abandoned animals—so far, six rabbits, six goats, two sheep, one horse, three cows and three chickens.