For many people, a special sale is just too attractive to walk away from. {#blank#}1{#/blank#} But with sales items, how can you be sure you're really getting a good deal? If you understand some sales tricks, you will be able to make smart choices.

    Some tricks have been used by shopkeepers for ages. {#blank#}2{#/blank#} For example, if an item is US＄11.99 instead of US＄12.00, you'll feel like you're spending less money.

    Sellers sometimes reduce items by a certain amount. {#blank#}3{#/blank#} That means that even with the discount, you may still pay more than the original price.

    Shopkeepers clearly understand what makes you want to buy their products. But with a little preparation, you can avoid being cheated.

Tips for shoppers

*Always compare prices before buying anything.

*{#blank#}4{#/blank#} The more focused you are, the easier it is to make wise decisions.

*Don't shop when you are hungry. Studies show that you'll usually buy more than you originally planned.

*{#blank#}5{#/blank#} First ask yourself: Do I have the money to buy it? Will I use it? If not, walk away, but if so, go for it! That way you'll still feel good after you take your item home.

A．Know what you're looking for.

B．Watch for"Buy one, get one free"sales.

C．And that makes shop owners very happy!

D．One of the oldest is to make prices end in 99.

E．Don't buy something just because it's on sale.

F．Check for sales ads in the newspaper or online.

G．But before the sale begins, sellers might mark the prices higher.

    Whether you have a piece of land or a few pots on a balcony, plant a family garden: You'll all live healthier! Gardening is an easy activity to share and you'll harvest benefits along with your fresh vegetables, colorful flowers, and aromatic herbs. Even better, you don't have to wait for your plants to bloom to see those benefits.

    When parents and kids work together to plant and care for a garden, they can all enjoy these benefits:

    Physical activity: Gardening and yard work are mild exercise, which we all need every day (for at least 30 minutes). While tending your family garden doesn't require the intense activity of running or playing singles tennis, it's still beneficial to your health. For one thing, research shows that once you start gardening, you usually continue for more than 30 minutes. And gardening combines delicate skill strengthening and stretching.

    Lower stress, better mood: Gardening is excellent stress relief for good reasons: enjoying fresh air and sunlight, performance of relaxing tasks, and even contact with harmless bacteria in the soil that helps release serotonin (血清素) in the brain.

    Outdoor time: Children prefer spending a lot of time indoors, which can negatively affect their behavior and health. A family garden gets them outside enjoying and experiencing the natural world.

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

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

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

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

    People with bigger brains tend to score higher on standardized tests of intelligence, according to new study findings.

    However, the study author Dr. Michael A.McDaniel of the Virginia Commonwealth University in Richmond emphasized that these findings represent a general trend, and people with small heads should not automatically believe they are less intelligent. For instance, Albert Einstein's brain was "not particularly large", McDaniel noted." There's some relationship between brain size and intelligence on the average, but there's plenty of room for exceptions," he said.

    Interest in the relationship between brain size and intelligence grew in the1830s, when German anatomist(解剖学家) Frederich Tiedmann wrote that he believed there was "an unquestionable connection between the size of the brain and the mental energy displayed by the individual man". Since that statement, scientists have conducted numerous studies to determine if Tiedmann's assertion was correct. Most studies have looked into the link between head size and intelligence. More recently, however, researchers have published additional studies on brain size and intelligence, measured using MRI scan(核磁共振成像扫描).

    For his study, McDaniel analyzed more than 20 studies that looked into the relationship between brain size and intelligence in a total of 1,530 people. The studies showed that on the average, people with larger brain volume tended to be more intelligent. The relationship between brain volume and intelligence was stronger in women than men, and in adults than in children. McDaniel notes in the journal Intelligence.

    McDaniel is not sure why the relationship was stronger for adults and women. "Other research has shown that women, on the average, tend to have smaller brains than men, but score just as well—if not higher—in tests of intelligence," he said.

    McDaniel insisted that the relationship between brain size and intelligence is not a "perfect" one. "One can certainly find lots of examples of smaller-sized people who are highly intelligent," he said, "But, on the average, the relationship holds."

    More than two thirds of the world's polar bears will be wiped out by 2050, according to a shocking new study. By then, scientists say, global warming will have melted 42 percent of the Arctic sea ice. By 2100, only a very few of these important creatures will be left.

    The report has been produced by the US Geological Survey. The scientists have publicized their findings in the hope of influencing US Interior Secretary Dirk Kempthorne, who has been asked to put polar bears on the US endangered species list.

    Polar bears depend on floating sea ice as a platform for hunting seals, which are their main food. Without enough ice, polar bears would be forced to go onto the land, where they are poorly skilled hunters, and would be unlikely to adapt to the life on the land in time. Experts say few little bears would survive and the stress could make many females unable to get pregnant.

    The team of American and Canadian scientists spent six months studying bears, on the ground, from spotter planes and in the lab, using computer models. Some team members fear the result is even worse for the bears than what their report says. They say the Arctic is warming faster than anywhere in the world and much faster than their computer had been forecasting. Satellite observations have showed that the ice has decreased to an all­time low.

    However, not everyone in the scientific community believes that global warming is happening on such an alarming scale. Another investigation has found that polar bears are still being hunted by wealthy “sportsmen” who want their skins and heads. At least ten international companies offer bear­hunting trips.

    It's school time again! You're probably feeling excited and maybe a little sad for the vacation is over. Some kids feel nervous on the first day of school because of all the new things: new teachers, new friends, and maybe even a new school. Luckily, these "new" worries only stick around for a little while. Let's find out more about going back to school.

    Most teachers kick off the school year by introducing themselves and talking about what you'll be doing that year. Some teachers give students a chance to tell something about themselves to the rest of the class.

    When teachers do the talking on the first day, they often go over classroom rules so you'll know what's allowed and what's not. Pay close attention so you'll know if you need to raise your hand to ask a question and what the rules are about visiting the restroom.

    You might already know a lot of people in your class on the first day. But it's a great day to make new friends, so try to say "hello" to the kids you know and new ones that you don't. Make the first move and you'll be glad about what you did and so will your new friends!

    Most teachers let you pick your own seat on the first day, but by the second or third morning, they'll have mapped out a seating plan. It's a good idea to write down where your seat is in your notebook so you don't forget.

    Here are a few final tips for a fantastic(奇异的) first day: Get enough sleep. Have a healthy breakfast. Try your best. Develop good work habits, like writing down your assignments(作业) and handing in your homework on time. Take your time with schoolwork. If you don't understand something, ask the teacher.