As the father of a student, I have experienced first hand what a great teacher is. My son was in the 4th grade last year, and he had a teacher called Miss Green. I believe that when he is an adult he will surely look back on her as the best teacher he has ever had.

    My son has attention deficit disorder(注意力缺损症) that makes it a little more difficult for him to learn.She was able to change her teaching methods for him so that he could keep up with the rest of the class. As a result, he got straight As on many subjects. She regarded her class as a family and they even had their own class song. She would often have them sing it to encourage them and develop a team spirit for them. When she saw that they were no longer listening carefully to what she was teaching, she would have them close their textbooks, stand up all around the room and throw around a small football. This helped them clear their minds and then focus on the lesson again.Besides, she was quick to reply to any phone calls or emails from us and got rid of our worries about children quickly.

    When my son went to the 5th grade this year, we happened to pass her classroom.When she saw my son, her face lit up and she came out and hugged him.She generally loves all of the children in her classroom and that love really shows.I can only pray that my son will continue to get teachers just like her for the rest of his school years.

HOLIDAY FUN AT THE POWERHOUSE

500 HARRIS STREET ULTIMO·TELEPHONE

( 02 ) 9217 0111

    Join in the holiday fun at the Powerhouse this month linked to our new exhibition, Evolution & Revolution: Chinese dress 1700s to now. DON'T FORGET our other special event, the Club Med Circus School which is part of the Circus(马戏团)！150 years  of circus in Australia exhibition experience!

◆Chinese Folk Dancing: Colourful Chinese dance and musical performances by The Chinese Folk Dancing School of Sydney. Dances include: the Golden stick dance and the Chinese drum dance. A feature will be the Qin Dynasty Emperor's court dance. Also included is a show of face painting for Beijing opera performances.

    Sunday 29 June and Wednesday 2 July in the Turbine Hall, at 11：30 am & 1：30 pm.

◆Australian Chinese Children's Arts Theatre: Well­known children's play experts from Shanghai lead this dynamic youth group. Performances include Chinese fairy tales and plays.

    Thursday 3 to Sunday 6 July in the Turbine Hall, at 11：30 am & 1：30 pm.

◆Chinese Youth League: A traditional performing arts group featuring performance highlights such as Red scarf and Spring flower dances, and a musician playing Er Hu.

    Sunday 6 to Tuesday 8 July in the Turbine Hall, 11：30 am to 1：30 pm.

◆Kids Activity: Make a Paper Horse: Young children make a paper horse cut­out. (The horse is a frequent theme in Chinese painting, indicating a kind of advancement.) Suitable for ages 8～12 years.

    Saturday 28 June to Tuesday 8 July in the Turbine Hall, 12：00 pm to 1：00 pm.

◆Club Med Circus School: Learn circus skills, including the trapeze, trampolining and magic. Note only for children over 5. There are 40 places available in each 1 hour session and these must be booked at the front desk, level 4, on the day.

Tuesday 1 to Saturday 5 July at 11：30 am & 1：00 pm.

    Enjoy unlimited free visits and many other benefits by becoming a family member of the Powerhouse. Our family memberships cover two adults and all children under the age of 16 years at the one address.

    Members receive Powerline, our monthly magazine, discounts in the shops and the restaurants, as well as free admission to the Museum. All this for as little as $50.00 a year! Call (02)9217 0600 for more details.

    TESCO has announced it is banning the sale of energy drinks to teenagers, and that the big move will begin in weeks. The supermarket has joined a host of major names banning teenagers from buying high caffeine, high-sugar drinks. The government indicates that the principal question to be determined is whether the purchasing restrictions will apply at the age of 16 or 18.

    Theresa May said the consultation was linked to the government's childhood obesity (肥胖) strategy and said it was necessary to examine the consumption of energy drinks "often because they are sold at cheaper prices than soft drinks".

    The principal reason for the ban is the high level of caffeine in the energy drinks, which has been linked to a string of health problems for children, including head and stomach aches as well as sleep problems.

    Energy drinks often also have higher levels of sugar than soft drinks. According to government figures, sugared energy drinks have 60% more calories and 65% more sugar than normal soft drinks and sugar is one of the largest causes of obesity.

    Jamie Oliver said he welcomed the ban on energy drink sales because "too many children are regularly using them to replace breakfast" and "teachers from across the country have told me how their lessons are disrupted because of these drinks".

    A Downing Street source added that there is no evidence that energy drinks have any nutritional value in children's diet. That accounts for the government's action on measures to tackle childhood obesity and improve children's health.

    The move is the latest step in an approach in relation to childhood obesity and health. According to European Food Safety Authority research, two-thirds of 10 to 16-year-olds regularly consume energy drinks, along with 18% of 3 to 10-year-olds.

Terrific New Technologies

•A fashionable smart speaker

    The new Amazon Echo smart speaker has the same popular feature as the original-an always listening voice assistant ready to play music and news, set timers, and use third-party apps. Only now it's actually stylish. The $120 speaker comes in different finishes, including fabric and wood.

•A helping hand for parents

    10 Suzy Snooze helps babies and kids sleep so parents can catch up on their own sleep. It's a sound machine and a nightlight. It connects with an app over wi-fi and turns into an audio monitor. If a kid cries at midnight, it'll detect the sound and try to calm him back to sleep. It can also let early risers know when it's OK to get out of bed. Made by Bleep Bleeps, the $249 "smart nightlight" has an adorable little face.

•Safety for ding dongs

    Doorbells used to just ring, ding, and dong. But thanks to modern technology, doorbells can now double as Internet-connected- surveillance(监视) devices. Rings $249 Video Doorbell Pro can record HD video of your front steps, even at night. It includes motion sensors and two-way audio, so you can yell "get off my lawn" from anywhere. You can also use the app to see what's going on in front of your house while you're at work or in the backyard.

•The must-have kitchen gadget

    The Instant Pot makes food fast in one pot. The surprise kitchen hit is a combination of pressure cooker, rice cooker, slow cooker and even yogurt maker. It has sensors and settings to make cooking as safe as possible. Starting at $80, an Instant Pot can make dishes in less time than it typically takes to cook them.

Many scientists today are convinced that life exists elsewhere in the universe—life probably much like that on our own planet. They reason in the following way.

    As far as astronomers can determine, the entire universe is built of the same matter. They have no reason to doubt that matter obeys the same laws in every part of the universe. Therefore, it is reasonable to guess that other stars, with their own planets, were born in the same way as our own solar system. What we know of life on earth suggests that life will arise wherever the proper conditions exist.

    Life requires the right amount and kind of atmosphere. This eliminates(除去) all those planets in the universe that are not about the same size and weight as the earth. A smaller planet would lose its atmosphere; a larger one would hold too much of it.

    Life also requires a steady supply of heat and light. This eliminates double stars, or stars that flare up suddenly. Only single stars that are steady sources of heat and light like our sun would qualify.

    Finally, life could evolve(进化) only if the planet is just the right distance from its sun. With a weaker sun than our own, the planet would have to be closer to it. With a stronger sun, it would have to be farther away.

    If we suppose that every star in the universe has a family of planets, then how many planets might support life? First, eliminate those stars that are not like our sun. Next eliminate most of their planets; they are either too far from or too close to their suns. Then eliminate all those planets which are not the same size and weight as the earth. Finally, remember that the proper conditions do not necessarily mean that life actually does exist on a planet. It may not have begun yet, or it may have already died out.

    This process of elimination seems to leave very few planets on which earthlike life might be found. However, even if life could exist on only one planet in a million, there are so many billions of planets that this would still leave a vast number on which life could exist.

Plants may tell us when they're in trouble.Thirsty tomato and tobacco plants make clicking sounds,researchers have found.The sounds are ultrasonic (超声波的),meaning they are too high-pitched for human ears to hear.But when the sounds are transformed to lower pitches,they sound like popping bubbles (爆破的泡泡).Plants also make clicks when their stems (茎) are cut.

"It's not like the plants are screaming," says Lilach Hadany,an evolutionary biologist working at Tel Aviv University in Israel."Plants may not mean to make these noises.We've shown only that plants create informative sounds."

Hadany and her colleagues first heard the clicks when they set microphones next to plants on tables in a lab.The microphones caught some noises.But the researchers needed to make sure that the clicking was coming from the plants.So,the scientists placed plants inside soundproof boxes in the basement,far from the noise of the lab.There,microphones picked up ultrasonic pops from thirsty tomato plants.Though it was outside humans' hearing range,the clicking made by plants was about as loud as a normal conversation.

Cut tomato plants and dry or cut tobacco plants clicked,too.But plants that had enough water or hadn't been cut stayed mostly quiet.Wheat,corn and grapevines also made sounds when stressed out.

The researchers don't yet know why plants click.Bubbles forming and then popping inside plant tissues that transport water might make the noises.But however they happen,pops from crops could help farmers,the researchers suggest.Microphones,for example,could monitor fields or greenhouses to detect when plants need to be irrigated (灌溉).

Hadany wonders whether other plants and insects already tune into plant pops.Other studies have suggested that plants respond to sounds.And animals from pests (害虫),moths to mice can hear in the range of the ultrasonic clicks.Sounds made by plants could be heard from around five meters away.Hadany's team is now studying what the living things near the plants will do after hearing the sounds.