If you see a group of people dancing and singing on the street or in the railway station,  you don't need to feel surprised．They are a flash mob （快闪族）, which is a group of people who come together suddenly in a public place, do something unusual for a brief period of time,  and then quickly break up．They are usually organized with the help of the Internet or other digital communication network．At a predetermined time, they gather and perform some  distractions（消遣） such as waving their hands and exchanging books, Then, they quickly break up before the police can arrive．Using mobile phones, the flash mob can change its location if the first one has been replaced for any reason．

    Bill Lasik, senior editor of Harper's Magazine, organized the first flash mob in Manhattan in May 2003 and the first successful flash mob came together on June 3, 2003 - after the first try was foiled at Macy's department store．Lasik claimed that the activity was designed to make fun of hipsters （起时髦的人）, and call attention to the cultural atmosphere．

    Flash mob gatherings can sometimes shock people．Such an activity might seem amusing and untrue, but it also might frighten people who are not aware of what is taking place．Undoubtedly, flash mobs can serve as good political tools in any direction．They also have great economic potential, such as using flash mobs to advertise a product．

    The flash mob is now becoming more and more popular．People use it to do many things．For example, in 2009, Michael Jackson's fans took part in a flash mob to remember him．Hundreds of his fans gathered singing and dancing Michael's famous song "Beat It" together．Flash mobs give people from all walks of life an opportunity to come together to create a memory．

    Most people would say the sea is blue and green. But the people who live near the coast of Zhejiang may say it is red. It is not people who caused the colour change, but very small living thing in the sea. They are algae(藻类)and protozoa(原生动物). They come in many different colours; red, yellow or brown. Red is the easiest of those to see so when this happens people call it a “red tide.”

    Red tides only happen when conditions in the sea are right. In the past few years, factories and people have been putting more chemicals into the sea. These chemicals help algae and protozoa to grow very quickly. The temperature of the sea is also important. Red tides usually happen at 20 to 30 degrees Celsius. Red tides often happen in dry, warm areas where there is little wind. Living things grow easily in these places. Sometimes fishermen help red tides by mistake. They put small sea animals into the water for food to help fish grow.

    Those living things do more than change the colour of the water-they also put poison and mucus(黏液)into the sea. This is had for fish. The poison is bad for their brains. And too much mucus in the sea fills up fish's gills(鳃) so they can't breathe. Lots of dead fish and other sea animals are now washed up on Chinese beaches.

    Red tides can be bad for people too. We shouldn't eat fish from red-tide waters. The algae gets inside of fish and it smells bad. It can make your eyes water. If people eat fish with too much algae inside they could die.

    Fishermen in Zhejiang are having a hard time right now. Because of the red tide, they are selling 30% less fresh seafood than usual.

    In China red tides usually happen in May and June around places like Fujian Guangdong and Hong Kong.

    Many other countries sometimes also have red tides. But it seems that we have few ways to stop red tides. They can last as long as 16 months.

                                                                                                  Chinese International School

    Application Form

    Before an applicant can be invited to take part in an assessment, an application form should be returned to the Admissions Office, and the application fee of HK$1,000 cannot be returned. For overseas applicants wishing to pay in currencies other than HK dollars, the fee is US$145. Checks are also good for payment to “Chinese International School”.

    The application should include

    Applicants' academic report from the last school year.

    A recent passport-sized photo (attached to the application form).

    A copy of the applicant's Hong Kong ID card or a passport showing a valid Hong Kong visa.

    Only for applicants applying under a Corporate Nomination (提名) Right：A company letter confirming the nomination.

    Please note that the application fee is non-refundable. Applicants who would like to re-apply for another academic year are asked to submit a new application and application fee.

    Acceptance

    Applicants will be informed of their acceptance status in writing by postal mail. Initial (最初的) offers for Reception will be sent out from late March once all assessments have been completed.

Some applicants who have been assessed may be held on a reserve list. Acceptances may also be made on a conditional basis among the applicants on the reserve list.

    Applicants who have been assessed but who have not been admitted are welcome to reapply for the next academic year. Please note that such applicants will be asked to submit a new application and application fee.

    Confirmation of Acceptance and Enrollment (录取)

    Once an applicant has been admitted, the applicant family will be asked to confirm acceptance and hold the student's place with immediate payment of the required fees for the Nomination Right (HK$ 500), plus the sum of HK$ 7,500 as the first tuition payment.

    In addition, enrollment will not be considered complete until the following have been received, normally one month before the start of the new school year

    Physical examination results           Tuition (first month)

    In 1943, when I was 4, my parents moved from Coeur d'Alene, Idaho, to Fairbanks, Alaska, where adventure was never very far away.

    We arrived in the summer, just in time to enjoy the midnight sun. All that sunlight was fantastic for Mom's vegetable garden. Working in the garden at midnight tended to throw her timing off, so she didn't care much about my bedtime.

    Dad was a Railway Express agent and Mom was his clerk. That left me in a mess. I usually managed to find some trouble to get into. Once I had a little fire going in the dirt basement of a hotel. I had tried to light a barrel(桶) of paint but couldn't really get a good fire going. The smoke got pretty bad, though, and when 1 made my exit, a crowd and the police were there to greet me. The policemen took my matches and drove me home.

    Mom and Dad were occupied in the garden and Dad told the police to keep me, and they did! I had a tour of the prison before Mom rescued me. I hadn't turned 5 yet.

    As I entered kindergarten, the serious cold began to set in. Would it surprise you to know that I soon left part of my tongue on a metal handrail at school?

    As for Leonhard Seppala, famous as a dog sledder, I think I knew him well because I was taken for a ride with his white dog team one Sunday. At the time I didn't realize what a superstar he was, but I do remember the ride well. I was wrapped (包裹) heavily and well sheltered from the freezing and blowing weather.

    In 1950, we moved back to Coeur d'Alene, but we got one more Alaskan adventure when Leonhard invited us eight years later by paying a visit to Idaho to attend a gathering of former neighbors of Alaska.

    Smart Kids is a collection of one hundred events scheduled in October. This year, it is experimenting with Pay What You Decide (PWYD). That is, you can decide to pay what you want to or can afford, after you have attended an event. You can pre-book events without paying for a ticket in advance. Here are some of the director's picks.

    Walk on the Wild Side

    Not ticketed, Free

Join storyteller Sarah Law to hear science stories about animals. Along the way you'll meet all sorts of beautiful creatures and discover life cycles and food chains. Best suited to children aged 5-9. Children under 8 must be accompanied by an adult.

    Introduction to Waves

    Pre-book, PWYD

    Subjects range from sound waves to gravity waves, and from waves of light to crashing waves on the ocean. Mike Goldsmith explores the fundamental features shared by all waves in the natural world.

Science in the Field

    Not ticketed, Free

This storytelling night features a scientist sharing his favourite memories of gathering first-hand data on various field trips. Come along for inspiring and informative stories straight from the scientist's mouth. Join Mark Samuels to find out more in this fun-filled workshop.

    Festival Dinner

Pre-book, £25 per person

Whether you want to explore more about food, or just fancy a talk over a meal, join us to mark the first science festival in London. Which foods should you eat to trick your brain into thinking that you are full? Find out more from Tom Crawford.

The Ebola virus is an infectious disease that for years had almost no treatments, and it kill s about half the people it infects. Now a new study published in The Lancet Infectious Diseases shows that a promising vaccine （疫苗）, named rVSV△G-ZEBOV-GP, doesn't just help to reduce infections, it also can cut those death numbers in half.

The vaccine is a single-dose （单剂） muscular one that causes cells to produce one of the virus's proteins. "Later, if the person is exposed to Ebola,"explains Rebecca Coulborn, a scientist with Epicentre, the medical research arm of Doctors Without Borders, "their immune system will recognize the viral protein. This recognition allows the immune system to be prepared to attack the virus and protect the person from Ebola virus disease."

Researchers showed rVSV△G-ZEBOV-GP was effective at reducing the risk of infection, but no one knew how capable it was of preventing death in someone who was vaccinated after becoming infected during an epidemic （流行病）. To figure it out, Coulborn and her colleagues focused their efforts on the second-largest Ebola outbreak ever recorded, which occurred in the Democratic Republic of Congo between 2018 and 2020.

"Every single Ebola health facility across the entire Ebola epidemic had a standardized list of all admissions," says Coulborn. This list included 2,279 confirmed Ebola patients, and it recorded whether or not each person had been vaccinated before they got sick—and if so, when they'd received the vaccine.

Coulborn found the death rate was 56% among the unvaccinated. But for those who'd received the vaccine, that rate was cut in half. This was true no matter when someone got vaccinated before the appearance of symptoms. Additionally, those who'd been vaccinated had less virus circulating in their bodies than those who hadn't. So the vaccine played an important role.

Rebecca Coulborn says she feels buoyed by the results—since they offer clear evidence that people who're at risk of contracting Ebola should be vaccinated early. It's an opportunity to cut chains of transmission （传播） and prevent an outbreak before it gains speed.