Sunscreens (防晒霜) can offer protection from two types of ultraviolet (UV) rays (紫外线): UVB, which according to the Skin Cancer Foundation, are the chief cause of sunburn and play a key role in the development of skin cancer, and UVA, which get through the skin more deeply and are largely responsible for skin aging and wrinkling, as well as skin cancer risk. The SPF (防晒指数) measurement on sunscreens refers to the UVB protection level — and the number may not mean what you think it does. SPF 15 doesn't protect you from 15% of UVB rays, just as SPF 100 doesn't protect you from 100% of the rays. In fact, as you get into the higher numbered SPF sunscreens (think: 50 and above), the difference in UVB protection is actually pretty small.

    Theoretically, though the increase in UVB protection with a super-high SPF sunscreen may be not worth considering, it may help, and certainly can't hurt, to use it — that is, as long as you do so correctly. “The only downside is whether you're giving yourself a sense of false security,” Dr. Gohara says.

    Indeed, as Dr. Wang also pointed out, when people choose increased SPFs, they may actually feel so protected by the product that they finally ignore proper sun protection. “When people use really high SPF products, they tend not to reuse, they tend to stay out in the sun much longer, and they don't use other protective measures such as clothing and hats,” he says. Regardless of any increase in protection that a high SPF may or may not offer, one thing is certain: It doesn't give your body a free pass from sunburns, aging, or cancers, and it doesn't protect you from those things for any greater length of time than the lower SPF options. Both Dr. Wang and Dr. Gohara emphasized that, no matter what the SPF is, it's important to reapply your sunscreen every two hours.

    It was Monday. Mrs. Smith's dog was hungry, but there was not any meat in the house.

    Considering that there was no better way. Mrs. Smith took a piece of paper, and wrote the following words on it: “Give my dog half a pound of meat.”Then she gave the paper to her dog and said gently:“Take this to the butcher(*person whose job is selling meat) and he's going to give you your lunch today.”

    Holding the piece of paper in its mouth, the dog ran to the butcher's. It gave the paper to the butcher. The butcher read it carefully, recognized that it was really the lady's handwriting and soon did it as he was asked to. The dog was very happy, and ate the meat up at once.

    At noon, the dog came to the shop again. It gave the butcher a piece of paper again. After reading it, he gave it half a pound of meat once more.

    The next day, the dog came again exactly at noon. And as usual, it brought a piece of paper in the mouth. This time, the butcher did not take a look at paper, and gave the dog its meat, for he had regarded the dog as one of his customers (*people who buy sth. from a shop).

    But, the dog came again at four o'clock. And the same thing happened once again. To the butcher's more surprise, it came for the third time at six o'clock, and brought with it a third piece of paper. The butcher felt a bit puzzled. He said to himself,“This is a small dog. Why does Mrs. Smith give it so much meat to eat today?”

    Looking at the piece of paper, he found that there were not any words on it!

    Rembrandt Harmenszoon van Rijn was one of the greatest artists of all time. He was born on July 15, 1606, in Leiden, Holland. Rembrandt began painting at an early age. At the age of 15, he traveled to Amsterdam to study art. But he soon returned home to paint on his own.

    Rembrandt's first paintings were of subjects from history. He used bright colors and shiny paints. These paintings were popular. Rembrandt became well-known in his community.

    In 1628, Rembrandt began to teach art. He was a respected teacher with many students. In 1632, Rembrandt again moved to Amsterdam. He began painting portraits (肖像) of many well-known people in Amsterdam. He soon became famous in Holland for his beautiful portraits.

    In 1634, he married a wealthy and educated girl named Saskia. She served as a model for many of his paintings. They moved into a large home where Rembrandt hung many of the paintings that he had collected. He enjoyed buying paintings by other artists.

    Rembrandt continued to succeed as an artist. But tragedy (悲剧) began to strike his family. Three of his four children died at a very early age. His wife, Saskia, died in 1642.

    Rembrandt became very sad. He began to paint with darker colors. But somehow, his painting grew even more beautiful. He used dark colors around the figures in his paintings. The figures themselves were painted as if a soft light were shining on them. One of Rembrandt's most famous paintings, The Night Watch, is from this period.

    Rembrandt began to paint more for himself and less for other people. Although his work was excellent, he was not able to make enough money to keep his house.

    Until he died on October 4, 1669, Rembrandt continued to paint. Rembrandt created over 600 paintings, 300 etchings (蚀刻画), and 1,400 drawings. Some of his most fascinating paintings were the portraits that he painted of himself. About 100 self-portraits leave a great record of his lifetime.

    Dujiangyan is the oldest man­made water system in the world, and a wonder in the development of Chinese science. Built over 2, 200 years ago in what is now Sichuan Province in Southwest China, this amazing engineering achievement is still used today to irrigate over 6, 000 square kilometers of farmland, take away floodwater and provide water for 50 cities in the province.

    In ancient times, the region in which Dujiangyan now stands suffered from regular floods caused by overflow from the Minjiang River. To help the victims of the flooding, Li Bing, the region's governor, together with his son, decided to find a solution. They studied the problem and discovered that the river most often overflowed when winter snow at the top of the nearby Mount Yulei began to melt as the weather warmed.

    The simplest fix was to build a dam, but this would have ruined the Minjiang River. So instead Li designed a series of channels built at different levels along Mount Yulei that would take away the floodwater while leaving the river flowing naturally. Better still, the extra water could be directed to the dry Chengdu Plain, making it suitable for farming.

    Cutting the channels through the hard rock of Mount Yulei was a remarkable accomplishment as it was done long before the invention of gunpowder and explosives. Li Bing found another solution. He used a combination of fire and water to heat and cool the rocks until they cracked and could be removed. After eight years of work, the 20­metre­wide canals had been carved through the mountain.

    Once the system was finished, no more floods occurred and the people were able to live peacefully and affluently. Today, Dujiangyan is admired by scientists from around the world because of one feature. Unlike modern dams where the water is blocked with a huge wall, Dujiangyan still lets water flow through the Minjiang River naturally, enabling ecosystems and fish populations to exist in harmony.

    If a family member blames you for something you have done, it is important to be careful about how you defend yourself. It is not a good idea to use ways that cause hurt, even if they would help you make a valid point. If you can think of an instance where the other person has done exactly what they accuse you of, for example, it would not be good manners to throw it in their face. You should only bring it up if you don't have a choice. Then, you should make sure that you do it respectfully.

    Even if a family member intentionally goes against reasonable wishes you may have, you should understand that people see even the most fundamental things in very different ways. Remember that people are different. If you consider any noise after midnight to be intolerable, for example, others may see it is completely acceptable. It can take them a great deal of time to change their behavior for a demand that they do not understand.

    Think about the family conflicts that you are worried about now. Check to see if your parents had similar problems. People who grow up with parents who fight unfairly often repeat the same behavior. Consider changing the unfair habits that you grew up with.

    Understand that memories tend to change. In long-standing family disputes, all parties involved tend to have completely different recollections of the original problem.

    Families are a curious concept—while family members often feel nothing but annoyed for one another, they will also often be there for them if they should ever be in serious trouble. When you feel resentment for someone, think about how far you would go for them if they happened to be in trouble. It could help soften you. Think about how you care for the other person.

    Who decided that blue jeans and T-shirts are "cool" for kids to wear today? Who designs the clothes you see for sale in stores? All of these questions concern the world of fashion.

    Fashion refers to the styles of dress that are currently popular. Fashion goes beyond just clothes, though. It's important for some people to wear only the latest fashions and styles. For others, though, keeping up with trends isn't that important. The one thing that stays the same with fashion is this: it always changes!

    In the 1960s and 1970s, hippies made bell-bottomed blue jeans popular. In the 1980s, Michael Jackson made parachute pants (降落伞裤) all the fashion. Now try to find these items in today's clothing stores!

Why do fashions change? The answer is probably as simple as the fact that people change. Over time, the new replaces the old. People are influenced greatly by popular culture, including athletes, musicians, movie stars, as well as popular films, television shows, books and music. We are also influenced by the fashion industry's advertising.

    The stars of popular culture are always searching for a new angle to maintain (保持) their popularity. Often these new angles come in the form of new clothing or hairstyles. When people see these new styles, they often want to imitate their favorite stars. To do so, they seek out the latest fashions to make themselves look like the people they want to imitate. In this way, fashions evolve and change over time.

    For years, clothes have been used to separate people into groups. Even today, brand-name clothing that is more expensive than other types of clothing can be used by some people to distinguish themselves from others.

    Unfortunately, this can often have the effect of distancing certain groups from others. Don't forget that it's always OK to develop your own sense of style that is unique and separate from what the fashion world determines! Stay true to yourself and let your personality — not your clothes — speak for who you are!