You know that balloons must be kept away from sharp objects. They also needed to be kept away from flames. A fire can weaken the rubber and cause it to break. However, in this experiment you will find out how you can hold a balloon directly in a flame without breaking the balloon.

    Materials needed:

● two round balloons not inflated(充气的)

● several matches

● water

    Inflate one of the balloons and tie it. Place 1/4 cup of water in the other balloon, and then inflate it and tie it. Light a match and hold it under the first balloon. Allow the flame to touch the balloon. What happens? The balloon breaks, perhaps even before the flame touches it. Light another match. Hold it directly under the water in the second balloon. Allow the flame to touch the balloon. What happens to this balloon? It doesn't break.

    Why does the balloon with no water break in the flame? The flame heats the rubber of both balloons. The rubber of the balloon without water becomes so hot that it becomes too weak to resist the pressure of the air inside the balloon. However, when the balloon with water in it is placed in the flame, the water takes in most of the heat from the flame. Then, the rubber of the balloon doesn't become very hot, it doesn't weaken, and the balloon doesn't break.

    Water is a particularly good absorber(吸收者) of heat. It takes a lot of heat to change the temperature of water. On the other hand, when water cools, it gives off a great deal of heat. That's why areas near oceans or other large bodies of water don't get as cold in winter as areas at the same latitude(纬度) further inland.

Integrity

    Integrity is the quality of being honest and strong about what you believe to be right. The concept of integrity has played a key role in moral philosophy throughout history and is promoted in all societies because of its importance to social relations. Individual integrity is vital to society, one that enables people to make use of their capacity for critical reflection, does not force people to take up particular roles and does not encourage individuals to betray each other. Besides, societies can be favorable to the development of individual integrity.

    Individual integrity can lift up the spirits of the entire society. It can shape the lives of people living in a particular society, the lives of all fellow people and, in its broadest sense, even the destiny(命运) of a nation. By contrast, if those living in the society are corrupt, it could have bad effects, jeopardizing the healthy morality of the society.

    On the other hand, a society can be favorable to the development of individual integrity. Society expects and requires integrity. A society consisting of people of integrity, and people who never compromise on their principles, could have a positive mark on the personal development of its members. Being a part of such a morally lively community could serve as a basis for absorbing traits of good character. This could be of a distinct advantage to any individuals in the society.

    However, some social structures are of the wrong sort for some individuals to pursue(追求) integrity. If that is the case, we have to ask questions about the moral nature of society first before raising questions about individual integrity. Questions about integrity may turn out to be about what kind of society it is, rather than about the relationship between individual interests and characteristics of a society. The pursuit of adequate individual integrity often depends, not so much on understanding who one is and what one believes and is committed to, but rather understanding what one's society is and imagining what it could be.

    Under no circumstances can we underestimate the importance of human integrity in a society. People, who are honest, trustworthy, compassionate and caring, are the factors decisive in the growth of individuals as well as the development of a society.

    If you are looking for something fun and educational to do in Maryland, why not visit the Maryland Science Center? It is located at 601 Light Street, Baltimore, MD 21230.The ticket prices vary depending on ages, groups and the exhibits you choose.

    Introduction

    The Maryland Science Center is basically a museum, but it gives everyone a chance to learn through experience and play, rather than just glance at an exhibit.

    Activities

    You can learn about various topics, including outer space, the human body, dinosaurs, electricity, marine（海洋的）biology, energy, and much more. You can also take part in the interactive activities, such as racing bubbles, digging for dinosaur fossils, using puzzle pieces to construct cars, and so much more.

    The Davis Planetarium（天文馆）

    At the Davis Planetarium, you can lie back in a chair and look at the stars while still inside the Science Center. The stars will appear on the ceiling of the theatre as you watch them.

    There are different shows to catch at the Davis Planetarium. You can learn about the galaxy and astronomy during the Dark Matters show. Learn about the stars and planets during the Sky Live show. The One World One Sky show allows children to explore the stars. The Live from the Sun show will teach you all about the hot sun.

    The Kids Room

    For children, they can't miss the Kids Room. They will be able to play in a water area, construct dams and water towers, push buttons, ring doorbells, build with blocks, and more, and definitely they will learn a lot. In addition, there is also an area for kids of two years old and under, where they can crawl, walk and explore safely with soft toys.

    Sometimes the toughest thing about feelings is sharing them with others．Sharing your feelings helps you whether your feelings are wonderful or terrible．Sharing also helps you to get closer to people you care about and who care about you．But how?

    You can't tell your friends what's inside your backpack if you don't know what's in there yourself．Feelings are the same way．Before you can share them with anyone，you have to figure out what feelings you have．

    Making a list of your feelings can help．You can do this in your mind or by writing it out or even by drawing pictures．Is something bothering you? Does it make you frustrated or terrified? Do you feel this emotion only once in a while or much of the time?

    The way a person feels inside is important．If you keep feelings locked inside，it can even make you feel sick! But if you talk with someone who cares for you，you will almost always start to feel better．It doesn't mean your problems and worries magically disappear，but at least someone else knows what's bothering you and can help you find solutions．

    Your mom and dad want to know if you have problems and what's happening in your life．But what if a kid doesn't want to talk with parents? Then find another trusted adult，like a relative or a teacher at school．Maybe this person can help you talk with your parents about your problem or concern．

    Once you know who you can talk with，you'll want to pick a time and place to talk．You can talk publicly in your family．But some kids are more private than others and they will feel shy about sharing their feelings．Then find a quiet place or write it down on a piece of paper．A kid doesn't have to share every feeling he or she has．

    Antarctica's ice white environment is going green and facing other unexpected threats. Scientists say that as temperatures go up in the polar area, invading (入侵) plants and insects, including the flies, cause a major threat.

More and more of these invaders, in the form of larvae(幼虫) or seeds, are surviving in coastal areas around the South Pole, where the temperature has risen by more than 3℃ over the past three decades. Glaciers have melted, exposing more land which has been occupied by mosses that have been found to be growing more quickly and thickly than ever before—providing potential green homes for invaders.

    “The common house flies are a perfect example of the problem the Antarctic now faces from invading species,” said Dominic Hodgson of the British Antarctic Survey. “It comes in on ships, where it exists in kitchens and then at bases on the continent. It now has an increasing chance of surviving in the Antarctic as it warms up, and that is a worry. Insects like the house flies carry bacteria that could have a deadly effect on native lifeforms.”

    The Antarctic has several native species of insects. Together with its native mosses these are now coming under increased threat from three major sources: visiting scientists increasing numbers of tourists and global warming. However, it is global warming that is the main driver of the greening of Antarctica.

    In 2015, more than 38, 000 tourists visited Antarctica. “These tourists are often very careful about not leaving waste or having mud. But they could carry seeds or larvae on their boots when they set foot on the Antarctic, “ said Hodgson.

    More and more invasive insects and plants have been found on the Antarctic and have required removal. “The insects and plants that are native to Antarctica have survived there for thousands of years,” said Hodgson, “We have got to act now if we want to save the environment.”

    Imagine someone who has spent the majority of their life sitting with a sign on the side of the road and that very person giving someone their last 20 dollars. That's exactly what Marine Corps veteran (退伍军人) Johnny Bobbitt, 34, did in October in Philadelphia.

    Bobbitt served in the U.S. Marine Corps and worked as a paramedic (医务辅助人员) in Vance County, N. C. before he became homeless. Nobody knew how he got to where he was because he was discreet about that.

    One night in October, Bobbitt was sitting roadside with a sign in Philadelphia as usual, when Kate McClure of Florence Township, N. J. was driving home down Interstate 95 and ran out of gas. Scared and nervous, she got out of the car to head to the nearest gas station. As McClure was heading to the nearest gas station, she ran into Bobbitt and he told her to get back in the vehicle and lock the door. Minutes later, he appeared with a red gas can. He'd used his last $20 to buy her gas.

    After that unexpected meeting, McClure and her boyfriend, Mark D'Amico, who both live in New Jersey, visited Bobbitt several times to deliver gift cards, cash, snacks and toiletries. They then decided to create a fund raising page so he wouldn't have to spend the holidays sleeping on the street.

    McClure started the GoFundMe page on November 10. With the page, the couple hoped to raise $10,000, enough money for his rent, a reliable vehicle and up to six months' expenses. Bobbitt's story ran in a local paper. By November 15，more than 10,000 local people had made donations through the GoFundMe page and more than $300,000 had been raised.

    On Thanksgiving, Bobbitt was resting in a hotel, his feet up on the bed, drawing up a grand plan for his new life, thanks to several thousand dollars raised to repay him for a good deed.