In Western countries, bread is one of the most important foods. When they get up in the morning many people eat toast (烤面包). They spread butter and jam on their toast. People eat bread at other times of the day too. For example, at main meals, they often eat bread with soup.

    It's also very common to eat sandwiches. A sandwich is two pieces of bread with a filling inside - salad, cheese or fish. A hamburger is a kind of sandwich.

There are many different kinds of bread. Some are special to some countries. For example, the baguette (法国棍子面包) is a long, thin loaf that began in France.

    There is also white bread and whole-wheat (全麦面) bread. What's the difference? White bread is refined (精制的). It has things taken out of it to make it softer and easier to eat. The trouble is, white bread also has lots of goodness taken out. Although some people dislike the taste of whole-wheat bread, it is much healthier.

    Some kinds of bread have additives (添加剂). They are put into the bread for many reasons. Some additives are good for you - for example vitamin C. Others are there to make the bread last longer. Still others to make it taste better - but they do not necessarily make the bread healthier to eat!

    San Francisco is a wonderful vacation destination that offers many different things to see and to do. The best way for a traveler to get a feel for the city is to take one of the many different tours there.

    Foot. When touring the city by walking, you aren't going to walk much. There are far more benefits to touring the city on foot, though. This kind of tour allows you to see many of the buildings. It usually makes you see a more localized neighborhood level.

    Water. The waters of San Francisco Bay have played an important role in the city's development over the last century. Touring San Francisco by water is a completely unique way for you to see this wonderful city.

    Bus. If you want to get a great feel for the layout of the city, one of the best things you could do is book a tour through our company. A bus tour of San Francisco is one of the most complete ways to experience the city.

    Air. While it is the most expensive way to see San Francisco, it is also one of the most unique and thrilling ways to see the city. Seeing the city from high above allows you to get a good feel for the layout of the city as tour guides point out landmarks and attractions. If you decide to tour San Francisco from the air, you'll get memories that you won't forget forever.

    We are a travel agency with good service. For more information, please click here.

    Chris Thomas used to think of Facebook as just a platform to get in touch with his friends. He now believes the social networking service with saving his life. The 28－year－old was diagnosed with muscular dystrophy(肌肉萎缩症) nine years ago and has relied on a wheelchair ever since.

    On July 15，2015，Thomas was getting ready for bed in his apartment，when a shelving(架子) fell onto his wheelchair and knocked him over，causing him to fall and hit the back of his head. After waking up from a few minutes of coma(昏迷)，he realized he couldn't reach the string used to get the doorkeeper's attention.

    His phone was nearby and had the Facebook application conveniently open，so he posted a status update that immediately got his friends worried—even some he hadn't spoken to in years. “It was amazing，friends from six different states who didn't know each other were connecting with each other to get me help，” Thomas said. “Now that's the power of social media! You have hundreds of people at your fingertips.”

    Eight minutes after the status went up，an old friend，Leah，got in contact with Thomas' friend Brad，whose wife was in the neighborhood，and before you knew it there were 12 Facebook friends in his apartment，who took him to the hospital at once. They showed up to the rescue at the perfect time. Minutes before they arrived，Thomas thought he was going to have a panic attack，which he often suffers from because of his illness，but he's doing better now.

    “It felt good to know that my friends，even those I haven't spoken to in the past，came to save me，” Thomas said. “They all came together .I would've never imagined it.”

    A good disguise keeps you hidden, right? Well, sometimes the best disguise is actually the most dazzling because research reveals that flashy metallic iridescence(金属彩虹色) can visually puzzle predators, which allows colorful prey to survive another day. Those surprising results appear in the journal Scientific Reports.

    Shining iridescent color, which changes depending on the angle from which it's viewed, is favored by everything from birds to beetles and blossoms to butterflies.

    "And in our research group we are of course interested in why this vivid metallic color is so widespread in nature." Karin Kjernsmo of the University of Bristol adds that in some cases the showy splashes of light are a sexual strategy. " Here I would like to point out that in some species, particularly those that display strong sexual dimorphism(雌雄两性), such as birds of paradise or some butterflies or fishes, the occurrence of iridescence is most likely driven by sexual selection. For example, in many of these cases it is the males that have these vivid iridescent colors and they use them in mate choice or they use them as a signal to attract mates."  But iridescence also shows up in situations where reproduction is not an issue. " So what we are studying now is whether natural selection imposed by predation(捕食行为) could explain the occurrence of iridescence in prey animals."

    The idea that eye­catching colors could be used as a cover­up isn't a new one." The father of camouflage theory, Abbott Thayer, really believed that iridescence should be categorized as a camouflage strategy. And he wrote in his famous lifework Concealing­Coloration in the Animal Kingdom, already in 1909, that 'brilliantly changeable or metallic colors are among the strongest factors in an animal's concealment'. And this sounds like a completely unreasonable thing to say, because how can colors that are both brilliant and changeable contribute to animal's concealment？"

    "In a similar way, we were asking whether iridescence, due to its changeability, could work as a form of camouflage by preventing shape recognition." Kjernsmo and her colleagues trained bumblebees to associate a particular shape—a circle or an oval—with a sugar reward. And they found that the bees, when given a choice, would preferentially visit the shape they knew to be sweet. But when the shapes were iridescent, the bees had trouble telling them apart. "It seemed that the strikingly iridescent surfaces on our targets visually broke up the otherwise recognizable shape of the targets, which made them hard to distinguish." As for making use of this method for hiding in plain sight, "Any practical applications is of course directly linked to any industry that has an interest in camouflage, that is how to conceal objects or make them more difficult to recognize." The researchers are currently conducting experiments with birds, which often prey on iridescent insects to see if it helps to have a bird's­eye view.

    Over the past century, an alarming number of animals have become endangered or even extinct. Below are some animals whose numbers have been rapidly dropping in recent years.

    Panda Bear

    One of the biggest reasons contributing to the decline in the panda species is the destruction of its natural habitat. Farmers in China have gradually been claiming more and more of the land. As a result, pandas are forced to move away to places where it is hard to find bamboo for food.

    Green Turtle

    The green sea turtle species has survived for several millions of years, so you might wonder why it's only becoming endangered now. A major cause is the change in climate and temperature, which both affect the hatching rates of turtle eggs. Climate changes also cause violent weather and rising water levels to flood areas where turtles usually go to lay their eggs. Apart from this, oil spills and other poisonous pollution, as well as increased fishing activities can cause sickness, or even death to the green turtles.

    Cheetah

    Cheetahs are famous for being the fastest animal on land but even they can't run from some of the larger threats that have harmed them. Like the panda bears, cheetahs have gradually been losing their natural homes due to humans claiming land and developing in those areas. To make matters even worse, smaller animals move away when these areas are occupied, which means that the cheetah has less food! Don't forget that other large animals, such as lions, are also fighting for any food that they can find, so occasionally young cheetahs end up as prey too.

    Indian Elephant

    Elephants are extremely intelligent animals and also the largest mammals that live on land. Sadly, in Asia many elephants were killed so that people could remove their tusks to use as decorative objects. While this practice has been banned now, some people still illegally continue. Forests in India have also been steadily destroyed and elephants are sometimes killed when they end up on human territory.

I hadn't got exercise lately and felt a bit dizzy. I was a little1 . One of my friends invited me to show up to see a2 that they said would help me feel better. Little did I know that I was about to see something I would never forget.

They introduced a young3 , Mr Patrick Henry Hughes. He was4 onto the stage in his wheelchair and began to play the piano. His fingers5 across the keys as he made beautiful music. He then began to sing as he played, and it was even more beautiful. For some reason,6 , I knew that I was seeing something special. Ten minutes later, someone came on the stage and7 a video of Patrick Henry Hughes.

Patrick was born with no eyes and a tightening of the joints which left him8 for life. Before his first birthday, he9 the piano. On his second birthday, he asked to play it. His father was10 . "We might not play baseball, but we can play music together. "

Today, Patrick is a11 at university. His father attends classes with him and he has made nearly all "A" s. He is also a trumpet player of a band. He and his father do it together — they12 all the band practices and the half-time performance in front of thousands of people.

But even more than his13 musical talent, it was Patrick's attitude to gratitude that touched me. I will never forget that night, that smile, that music, but most importantly, that14 attitude to gratitude. Gratitude can change your attitude,15 your life forever.