Grandma celebrated her fifty-third birthday just weeks before grandpa died of cancer in 1965. Although his passing was very difficult for her, I think their shared struggle to make his life longer taught grandma that good health was not to be taken for granted, and she made up her mind to live her rest of her own life as fully and as long as she could. One day, when she announced to attend lessons at the Fred Astaire Dance Studio in Portland, Oregon, where she lived, we rolled-our eyes in embarrassment and helplessly wished she would just stay home and bake cookies as normal grandmothers did. Many years filled with countless dance lessons passed before we learned to appreciate the wonder of having a dancing grandma.

I suppose grandma's primary motivation for wanting to learn to dance was social. She had been a shy girl, always very tall and heavy, and had married into grandpa's quiet lifestyle before developing any elegance or confidence in her personal appearance. Dancing, on the other hand, filled her life with flash lights，wonderful parties, beautiful dresses, handsome young dance instructors, and the challenge of learning. Although the weekly dance lessons did not change her ample, two-hundred-pound figure, grandma surprised everyone with energetic performances on the dance floor, which soon gave her as much elegance and confidence as any Miss American competitor.

    Having taken weekly dance lessons for years, my grandma learned various dances easily and was soon participating in dancing matches all over the Northwest. When I was fourteen, grandma proudly invited me to watch her compete in one of these matches to be held in the grand ballroom of the Red Lion Inn. My attitude was still unenthusiastic at that point, but to make her happy, my mother and I attended the match. As if to prove me wrong, grandma made a wonderful showing in every event she entered. I thought she was truly the queen of the ball during the dance, and my thoughts were shared by the judges a short time later when she was awarded a gold cup for her outstanding performance.

    In my life, my grandfather has influenced me a lot. Ever since I was a little kid, I have always loved sports, especially football. My grandfather also enjoys sports and really loves football. He received a couple of awards in football matches. Through my three years so far in high school, my grandfather has helped me become a better player.

    Another reason why I admire my grandfather so much is because of his strong work ethic(道德). Ever since I was a little boy, my grandfather has taught me and shown me what good work ethic means. He is a good example. When he was a young man, his family owned a small store. He often helped his father run the store. He has also done several jobs in his life. He owned his own store when my mother was a young girl; he helped on a farm; he then had his own painting business. Now he is working at a Wal-Mart.

    Responsibility(责任) is something that I have struggled with in the past. My grandfather, on the other hand, is a very responsible person. That's why I am very responsible now, because of him. When he was in school, he was almost a straight A student. I, on the other hand, don't do so well. One day he had a talk with me about being more responsible. He helped me in school and made me realize how important grades are. Now I get almost As and Bs.

    Now you can see why I admire and respect my grandfather as much as I do. He is the best role model I have, and I will always look up to him.

    Over the past 10 years, developments in technology have moved the dream of personal fling vehicles closer to reality. The British company Malloy Aeronautics has developed a model of its flying bicycle. The company says its Hoverbike will be a truly personal flying vehicle.

    The company's marketing sales director Grant Stapleton says the Hoverbike is able to get in and out of small spaces very quickly and can be moved across continents very quickly because it can be folded and packed.

    Safety was the company's main concern when developing the Hoverbike. The designers solved this problem by using overlapping rotors(重叠旋翼) to power the vehicle. With adducted rotors(内转旋翼) the rider immediately not only protects people and belongings if he were to hit them, but if the rider ever were to crash into somebody or something, it's going to bring the flying vehicle out of the air. The company is testing two models of the Hoverbike.

    In New Zealand, the Martin Aircraft Company is also testing a full-size model of its personal flying device, called Jetpack. It can fly for more than 30 minutes, up to 1,000 meters high and reach a speed of 74 kilometers per hour.

    Peter Coker, one officer from the company said Jetpack “is built around safety from the start.” In his words, “Reliability(可靠性) is the most important part of it. We have safety built into the actual structure itself, very similar to a Formula One racing car.”

    Jetpack uses a petrol-powered engine. It also has a parachute(降落伞) that can be used if there should be an emergency(突发事件). It opens at very low altitude(纬度) and actually saves both the flying vehicle and the pilot in an emergency.

    Mr. Coker says Jetpack will be ready for sale to the public by the end of 2019. He adds it'll have a price of about $200,000.

    Bees in a colony work with each other to gather food, and they try to find the most nectar (花蜜)in the least amount of time possible. A small number of bees work as searchers, but when a good flower patch (花丛) is found, how do they tell other bees where to find it?

    Bees communicate flower location using special dances inside the hive, where bees live. One bee dances while the other bees watch. The dancing bee smells like the flower patch, and also gives the watching bees a taste of the nectar she has gathered. Smell and taste helps other bees find the correct flower patch. Bees use two different kinds of dances to communicate information: the waggle (摇摆) dance and the circle dance.

    Waggle dance

    The waggle dance tells the watching bees two things about a flower patch's location: the distance and the direction away from the hive.

A. Distance

    The dancing bee waggles back and forth as she moves forward in a straight line, then circlesaround to repeat the dance. The length of the middle line, called the waggle run, shows roughly how far it is to the flower patch.

B. Direction

    Bees know which way is up and which way is down inside their hive, and they use this to show direction. How? Bees dance with the waggle run at a specific angle away from straight up. Outside the hive, bees look at the position of the sun, and fly at the same angle away from the sun.

    Circle dance

    The circle dance tells the watching bees only one thing about the flower patch's location: that it is somewhere close to the hive.

    In this dance, the bee walks in a circle, turns around, then walks the same circle in the opposite direction. Sometimes, the bee includes a little waggle as she's turning around. The duration of this waggle is thought to indicate the quality of the flower patch.

    Petrol and diesel cars may still dominate our roads, but their days are numbered. A recent university study found that current electric cars could be used for 87 per cent of daily car journeys in the US. That figure could rise to 98 per cent by 2020.

One hurdle to the widespread adoption of electric cars has been ‘range anxiety'— drivers' concerns about running out of juice on a journey. While petrol stations are conveniently located across national road systems, the necessary network of electric charging stations is still being developed. That said, charging points are becoming increasingly common throughout the USA.

    Attitudes towards electric vehicles have changed quite considerably over the last few years. Not that long ago, electric cars were met with distrust, and their large price tags drove customers away. Thanks to improvements in battery capacity, recharging times, performance and price, the current generation of electric cars are starting to persuade critics. Plug-in cars will soon give internal combustion engine models a run for their money.

    As well as advancements on the road, electric vehicles are taking to the seas and skies. Electric boats are among the oldest methods of electric travel, having enjoyed several decades of popularity from the late 19th to the early 20th century before petrol-powered outboard motors took over. Now, the global drive for renewable energy sources is bringing electric boats back. Steps towards electric air travel are also being made, with Airbus and NASA among the organizations developing and testing battery powered planes. The experiments could soon make commercial electric flight a reality.

    Electric vehicles do not produce any emissions. Were the US to act on the study's findings and replace 87 per cent of its cars with electric vehicles, it would reduce the national demand for petrol by 61 per cent. However, because of the production processes and the generation of electricity required to charge these vehicles, they cannot claim to be completely emission-free. That said, as many countries continue to increase their use of renewable energy sources, electric vehicles will become even cleaner.

    I grew up on a farm outside Port Clinton, Ohio. I was the youngest son, with four brothers and four sisters, plus a girl my relatives took in when she was in sixth grade and was raised along with us.

    By the late 60s, most of us were married and had families of our own. One day, while we were visiting my parents in late summer or early fall, Dad mentioned he'd always wanted a Crimson King maple tree for the yard. Mom agreed that they were pretty.

    Like many parents, mine were hard to shop for, so I figured this was a great opportunity to get them something they'd appreciate. I checked the price at work and decided it was a bit more than I could afford but all of my brothers and sisters agreed to help.

    In northern Ohio, people don't plant maple trees at Christmas, so we decided to surprise Mom and Dad with a special Christmas in October before the ground froze. We asked my aunt if she'd help us with the trick, and she called my parents in advance to say she was coming for a Sunday visit. Then my sisters and sisters-in-law went into action, planning a big holiday turkey dinner.

    On the chosen Sunday, we all met at my house and loaded the trees in a pickup truck. I dressed up as Santa Claus, though at the time I weighed about 140, so all the padding(填料) in the world couldn't make me look like St. Nick. Then off we went, nine or ten cars loaded with people and food, plus the pickup truck.

    When the truck arrived at my parents' house, Dad came out of the back door, convinced something was wrong. He and Mom were amazed when we told them why we were there.

    When Christmas rolled around, of course, we couldn't go to our parents' house empty-handed, so Mom and Dad got double presents that year. Almost half a century later, I still drive by the old farm and smile when I see those big, handsome trees.