Radar（雷达） is an electronic device that detects planes, ships, coastlines, landmarks, and even storm clouds. The name radar comes from the first letters of the words radio direction and ranging. As the human eye uses light waves to see, radar “sees” with radio waves. Without radar, planes could not land safely in bad weather and ships could not move safely in thick fog{#blank#}1{#/blank#}

    In the 1800s it was discovered that radio waves could be reflected from objects. But scientists did not make great advances in radar research until the 1930s, when the world was threatened by war{#blank#}2{#/blank#}It has been used widely in almost every conflict since then.

    Echoes make it possible for radar to work. When a beam of radio waves is sent out, it strikes on an object and returns an echo. This echo is picked up by radar and recorded on a screen similar to television screen. On the screen an observer sees a flash, or a blip, that shows the direction and distance of the object{#blank#}3{#/blank#}

    Airport control towers use radar to guide planes in for safe landings. Almost all large ships depend on radar to prevent collisions with icebergs or other ships{#blank#}4{#/blank#}Weather forecasters “see” the size, direction, and speed of storms on radar screens. Astronomers can even use radar to measure accurately the distance to the moon. Thus, the device has generated major advancements.

    {#blank#}5{#/blank#} Huge radar antennas have been installed all over the United States. They guard us against possible enemy attacks. We have ballistic—missiles (战略导弹)warning systems that can alert us to attacks when missiles are more than 1,000 miles away. Other radar systems warn us against enemy aircraft and even spying space satellites.

A. Police track speeders in radar-equipped cars.

B. These measurements are now highly accurate.

C. The device can be used in a wide range of fields.

D. During World War II many countries used radar effectively.

E. It is therefore especially valuable to shippers and travelers.

F. Today radar is used by commercial airliners and weather forecasters.

G. Strengthening national defense is one of radar's most important functions.

Hear the Wind Blow by Mary Downing Hahn

    On a cold, snowy night, 13-year-old Haswell Magruder makes an important decision. A wounded Confederate soldier appears at the family's farm, and Haswell convinces his mother to take the man in. Unfortunately, this sets off a horrific chain of events that leaves their house burned to the ground and their farm in ruins. With no home left, Haswell sets out in search of his older brother, a Confederate soldier.

    Ghosts of Greenglass House by Kate Milford

    Thirteen-year-old Milo is, once again, spending the winter holidays stuck in a house full of guests who are not what they seem. There are fresh clues to uncover as friends old and new join in his search for a mysterious map. The exciting ending to the beloved book is sure to thrill both fans and newcomers.

    Marge in Charge by Isla Fisher

    Jemima and Jake Button don't know what to make of their new babysitter, Marge. When she first arrives, she's dressed like a grandma and looks very serious. But as soon as Mommy and Dad are gone, Marge lets down her hair and the adventures begin. Jemima and Jake aren't supposed to shoot apple juice out of water guns, or throw impromptu (即兴的) concerts during music class—but with Marge here, everything's gone messy!

    Max Tilt: Fire the Depths by Peter Lerangis

    When 13 year old Max Tilt finds his great-great-grandfather Jules Verne's unfinished, unpublished manuscript (手稿), The Lost Treasures, he doesn't realize that he's found the answers to all his problems. He realizes that the book holds the key to something incredibly valuable. A treasure that can save his house — and maybe his entire family.

    Orthopedic pillows are not just like any other ordinary pillow. These products are specially made to fulfill a specific function.

    People buy orthopedic pillows for several reasons. Sometimes people buy this type of pillow because their doctor has specifically recommended them to do so as part of a treatment and management plan for neck, back, or bone problems. In recent years, people have become more aware of the science behind orthopedic pillows, which accounts for the increase in the popularity of these pillows. There has been a lot of available orthopedic pillow information for anyone interested. The science behind these pillows has also advanced significantly over the years, which means that orthopedic pillows are now more effective and useful than ever.

    Orthopedic pillows help you maintain the right gesture. While traditional pillows may be very comfortable, they do not necessarily promote the proper gesture as you sleep, which is proved to be important for your health. It also helps you avoid waking up with a host of body aches and pains. Among the most common causes of back and neck pains is sleeping without adequate support. Orthopedic pillows can provide you with the necessary support that will keep these kinds of body pains away. The pillow is specifically designed to conform to the natural contours (轮廓) of your body, thus ensuring that your skeletal structure is kept in proper alignment (直线) throughout the night and that no part of your body is subjected to too much pressure, which leads to pain.

    Of course, it is understandable that you may find an orthopedic pillow a bit uncomfortable the first time you use it, but that is true with any new experience. The materials used in manufacturing these pillows are ideal for the kind of sleep that you are looking for.

    Just like any product in the market, there is a disadvantage to an orthopedic pillow as well. They are usually more expensive than traditional pillows. But, if you treat the purchase as an investment on your health, it may be a lot easier for you to part with the cash.

    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.

China's Tianwen 1 Mars probe (探测器) conducted its fourth orbital correction on Friday evening, as the spacecraft makes ready for its arrival in orbit around Feb. 10, according to the China National Space Administration.

The name comes from the long poem Tianwen, meaning Heavenly Questions or Questions to Heaven, written by Qu Yuan, one of the greatest poets of ancient China. In Tianwen, this name conveys the Chinese nation's steady effort in pursuing truth and culture of exploring nature and the universe. CNSA also unveiled (发布) the logo of China's planetary exploration missions, featuring the letter C, signifying China, international cooperation and capacity of entering space.

Tianwen I has flown for 197 days and more than 465 million kilometers on its journey to the planet. It is now around 184 million km from Earth and I. I million km from Mars. Depending on the two planets' orbits, Mars is between 55 and 400 million km from Earth. Mars probe Tianwen I is seen in its first selfies in space on Oct. 1, 2020. The administration also published a black-and-white picture of Mars taken by Tianwen I, the first snapshot (抓拍的照片) from the Chinese craft.

Tianwen I, the country's first independent Mars mission, was launched by a Long March 5 heavy-lift carrier rocket on July 23 from the Wenchang Space Launch Center in Hainan province, kicking off the nation's planetary exploration program.

A successful landing would make China only the second nation to place a spacecraft on the Martian planet. China would also be the first to successfully orbit, land and deploy (部署) a vehicle in the same mission. According to experts, searching for signs of life on Mars will be the first and foremost scientific goal. China is open and inclusive in the development of its space technology not least because it believes that the exploration of outer space should help build a community with a shared future for mankind.

If you've ever seen a sparrow steal your dog food or a crow open a garbage bag, you get a sense of that some birds have learned to take advantage of new feeding opportunities—a clear sign of their intelligence. Scientists have long wondered why certain species of birds are more innovative than others, and whether these capacities stem from larger brains or from a greater number of neurons（神经元） in specific areas of the brain.

It turns out that it's a bit of both, according to a recent study by an international team that included members from McGill University published in Nature Ecology and Evolution.

The researchers used a new technique to estimate the number of neurons in a specific part of the brain called the pallium in 111 bird species. The pallium in birds is equal to the human cerebral cortex（大脑皮层）, which is involved in memory, learning, reasoning, and problem-solving, among other things. When these estimates about neuron numbers in the pallium were combined with information about over 4,000 feeding innovations, the team found that the species with the higher numbers of neurons in the pallium were also likely to be the most innovative.

"The amount of time chicks spend in the nest as their brains develop might also play acrucial role in the evolution of intelligence," says McGill University Emeritus Professor Louis Lefebvre who spent more than 20 years gathering examples of feeding innovations. "Larger species of crows and parrots, which are known for their intelligence, spend longer in the nest, which allows more time for the brain to grow and accumulate pallial neurons."

The results of the study help to deal with previously opposed views of the evolution and significance of brain size and show how a life-history perspective helps to understand the evolution of cognition.