It is bad to have food stuck between your teeth for long periods of time. This is because food attracts germs; germs produce acid, and acid hurts your teeth and gums. Flossing (使用牙线) helps to remove the food that gets stuck between your teeth. This explains why flossing helps to keep your mouth healthy, but some doctors say that flossing can also be good for your heart.

    It may seem strange that something you do for your teeth can have any effect on your heart. Doctors have come up with a few ideas about how flossing works to keep your heart healthy. One idea is that the germs that hurt your teeth can leave the mouth and travel into your blood.Germs that get into the blood can then attack your heart. Another idea is based on the fact that when there are too many germs in your mouth, the body tries to fight against there germs. For some reason, the way the body fights these mouth germs may end up weakening the heart overtime.

    Not every doctor agrees about these ideas. Some doctors think that the link between good flossing habits and good heart health is only a coincidence. The incidence (发生率) of two or more events is completely random, as they do not admit of any reliable cause and effect relationship between them. For example, every time I wash my car, it rains. This does not mean that when I wash my car, I somehow change the weather. This is only a coincidence. Similarly, some doctors think that people who have bad flossing habits just happen to also have heart problems, and people who have good flossing habits just happen to have healthy hearts.

    The theory that flossing your teeth helps to keep your heart healthy might not be true. But every doctor agrees that flossing is a great way to keep your teeth healthy. So even if flossing does not help your heart, it is true to help your teeth. This is enough of a reason for everyone to floss their teeth every day.

    Parents have widely different views on the problem of pocket money. Four new fathers were asked this question and this is how they answered.

    Ashish Khanna: Although many argue that pocket money helps develop children's sense of value, I don't agree. I wouldn't give my child any pocket money. First of all, I never got pocket money and I seem to have a good value for money. If my child ever needed something and I felt it was a reasonable（合理）request , I would buy it for him .

    Sharad Sanghi: No, I wouldn't give my child pocket money because I don't want to create the perception（观念） of “ her ” money and “ my ” money . Besides, if I refuse to buy her something that I think is bad for her, she may buy it with her pocket money on the sly. In this way, I would lose control over my child's requests. I feel it also encourages children to care more about money than anything else. I don't want my child to start judging(评判) other children by the amount of money or pocket money they have.

    Rakesh Shah: Yes, I would give my child pocket money. I feel that children should learn to spend money intelligently and not go overboard spending. They will learn what their limitations（限制）are and feel the difficulty when they have to pay for something that is over their own pockets .

    Rajiv Patel: Yes, I would give my child pocket money because it is important that she learns to manage money. I will give her a fixed amount every month and if she spends the money before the month is over, then she will learn a lesson and not spend money so freely.

    Vikram Desai: Yes, I would certainly give my child pocket money. But I would not give it to him on a weekly or monthly basis. He would have to earn it. If he helped me finish some of my jobs or helped his mother with housework, I would reward him. This helps him realize that “money does not grow on trees” and it requires hard work to earn money.

    It is believed that some of animals think a great deal. Many of them are like children in their sports. Some birds are very lively in their sports; and the same is true with some insects. The ants, hardworking as they are, have their times for play. They run races; they wrestle; and sometimes they have mock fights together. Very busy must be their thoughts while engaged in these sports.

    Animals think much while building their houses. The bird searches for what it can use in building its nest, and in doing this it thinks. The beavers think as they build their dams and their houses. They think in getting their materials, and also in arranging them, and in plastering them together with mud. Some spiders build houses which could scarcely have been made except by some thinking creature.

    As animals think, they learn. Some learn more than others. The parrot learns to talk, though in some other respects it is quite stupid. The mocking bird learns to imitate a great many different sounds. The shepherd dog does not know as much about most things as some other dogs, and yet he understands very well how to take care of sheep.

    Though animals think and learn, they do not make any real improvement in their ways of doing things, as men do. Each kind of bird has its own way of building a nest, and it is always the same way. They have no new fashions, and learn none from each other.

    It is plain that, while animals learn about things by their senses as we do, they do not think nearly as much about what they learn, and this is the reason why they do not improve more rapidly. Even the wisest of them, as the elephant and the dog, do not think very much about what they see and hear. Nor is this all. There are some things that we understand, but about which animals know nothing. They have no knowledge of anything that happens outside of their own observation. Their minds are so much unlike ours that they do not know the difference between right and wrong.

    Sandra Cisneros was born in Chicago in 1954 to a Mexican American family. As the only girl in a family of seven children, she often felt like she had “seven fathers,” because her six brothers, as well as her father, tried to control her. Feeling shy and unimportant, she retreated(躲避)into books. Despite her love of reading, she did not do well in elementary school because she was too shy to participate.

    In high school, with the encouragement of one particular teacher, Cisneros improved her grades and worked for the school literary magazine. Her father encouraged her to go to college because he thought it would be a good way for her to find a husband. Cisneros did attend college, but instead of searching for a husband, she found a teacher who helped her join the famous graduate writing program at the University of Iowa. At the university's Writers' Workshop, however, she felt lonely－a Mexican American from a poor neighborhood among students from wealthy families. The feeling of being so different helped Cisneros find her “creative voice”.

    “It was not until this moment when I considered myself truly different that my writing acquired a voice. I knew I was a Mexican woman, but I didn't think it had anything to do with why I felt so much imbalance in my life, but it had everything to do with it! That's when I decided I would write about something my classmates couldn't write about.”

    Cisneros published her first work, The House on Mango Street, when she was twenty-nine. The book talks about a young Mexican American girl growing up in a Spanish-speaking area in Chicago, much like the neighborhoods in which Cisneros lived as a child. The book won an award in 1985 and has been used in classes from high school to graduate school level. Since then, Cisneros has published several books of poetry, a children's book, and a short-story collection.

    A new officer with the Huntington Park Police patrols (巡逻) local parks 24 hours a day seven days a week. He doesn't need rest, coffee breaks, a salary or medical insurance, and that is because it is a Robocop.

    The main function of the Robocop is to scan and film the surroundings. Besides cameras with night vision that report 360 degrees, it also has a distress button which is located here, so if somebody is to need assistance or they want to contact the communication center, they can do it by way of that distress button. There are people that are monitoring on the other end.

    This newest police employee is self-charging. It's easy to program it and make changes to the software if necessary. Its maintenance (维护) costs are roughly 75 thousand dollars a year. It travels the entire park. It is a programmed path, but the police are able to change the path and adapt it.

    The Robocop can record the license plates (车牌) of passing cars and check them against an online database of stolen cars. It can also help locate a lost iPhone because it is able to determine a smartphone's MAC address. The police can see from the robot if something wrong happens and then come and figure it out.

    The Robocop can't replace its human handlers. The whole goal is to give police more time to do things machines can't do. The police have been having some concerns about safety of the parks and want an extra set of eyes that will help patrol a 24/7.Robocop's creators believe this model known as K5 is best used for providing security at public places like hospitals, parking lots, parks and airports. So far, it seems to be working out just fine.

In life, once on a path, we tend to follow it, for better or worse. What's sad is that even if it's the latter, we often accept it anyway because we are so used to the way things are that we don't even recognize that they could be different. This is a phenomenon psychologist call functional fixedness.

This classic experiment will give you an idea of how it works and a sense of whether you may have fallen into the same trap: People are given a box of tacks (大头钉) and some matches and asked to find a way to attach a candle to a wall so that it burns properly.

Typically, the subjects try tacking the candle to the wall or lighting it to fix it with melted wax. The psychologists had, of course, arranged it so that neither of these obvious approaches would work. The tacks are too short, and the paraffin (石蜡) doesn't stick to the wall. So how can you complete the task? The successful technique is to use the tack box as a candle-holder. You empty it, tack it to the wall. and stand the candle inside it. To think of that, you have to look beyond the box's usual role as a receptacle just for tacks and re-imagine it serving an entirely new purpose. That is difficult because we all suffer to one degree or another from functional fixedness.

The inability to think in new ways affects people in every corner of society. The political theorist Hannah Arendt coined the phrase" frozen thoughts" to describe deeply held ideas that we no longer question but should. In Arendt's eyes, the self- content reliance on such accepted "truths" also made people blind to ideas that didn't fit their worldview, even when there was plenty of evidence for them.

Frozen thinking has nothing to do with intelligence. She said," It can be found in highly intelligent people."