Many animals recognize their food because they see it.So do humans.When you see an apple or a piece of chocolate you know that these are things you can eat.You can also use other senses when you choose your food.You may like it because if smells good or because it tastes good.You may dislike sonic types of food because they do not look,smell or taste very nice.Different animals use different senses to find and choose their food.A few animals depend on only one or their senses,while most animals use more than one sense.

    Although there are many different types of food,some animals spend their lives eating only one type.The giant panda eats only one particular type of bamboo.Other animals eat only one type of food even when given the choice. A kind of white butterfly will stay on the leaves of a cabbage,even though there are plenty of other vegetables in the garden.However,most animals have a more varied diet.The bear eats fruits and fish.The fox eats small animals,birds and fruits.The diet of these animals will be different depending on the season.

    Humans have a very varied（广泛的）diet.We often eat food because we like it and not because it is good for us. In countries such as France and Britain,people eat foods with too much sugar.This makes them overweight,which is bad for their health.Eating too much red meat and animal products,such as butter,can also be bad for the health. Choosing the right food,therefore,has become an area of study in modern life.

    Every year gray whales swim a 10,000 miles round-trip, from the cold waters near Alaska, down the coast of North America to the warm waters near Mexico, and back again. It is one of the longest migrations (迁徙) of any mammal (哺乳动物).

    All day, all summer long, in the cold waters near Alaska, gray whales eat and eat.

    Instead of teeth, gray whales have baleen (鲸须) they use to get food from ocean water. They get big mouthfuls of muck (淤泥) from the ocean floor, then push that muck right back out through their baleen. The mucky water flows through, but tiny animals get trapped in the baleen and licked up.

    When the water starts to freeze, the whales begin their long trip south. They swim night and day, without stopping to eat or rest. During the long journey, migrating whales may push their heads out of the water to see where they are.

    Two months later, the whales reach Mexico. Babies are born here in warm, shallow (浅的) waters called lagoons (濒海湖). Ocean lagoons have no food for the adults, but the babies are safer here than in the open seas. All winter the babies grow big and strong.

    In spring first the dads and teenagers leave the lagoons, then the moms with babies. Migrating gray whales swim close to shore, especially moms with babies. The ice is melting up (融化) north, and it's time for the hungry whales to make the long journey back to their summer feeding grounds.

    Washington, D.C. Bicycle Tours

    Cherry Blossom Bike Tour in Washington, D.C.

    Duration: 3 hours

    This small group bike tour is a fantastic way to see a world-famous cherry trees with beautiful flowers of Washington, D.C. Your guide will provide a history lesson about the trees and the famous monuments where they blossom. Reserve your spot before availability—and the cherry blossoms—disappear!

    Washington Capital Monuments Bicycle Tour

    Duration: 3 hours (4 miles)

    Join a guided bike tour and view some of the most popular monuments in Washington, D.C. Explore the monuments and memorials on the National Mall as your guide shares unique facts and history at each stop. Guided tour includes bike, helmet, cookies and bottled water.

    Capital City Bike Tour In Washington, D.C.

    Duration: 3 hours

    Morning or afternoon, this bike tour is the perfect tour for D. C. newcomers and locals looking to experience Washington, D.C. in a healthy way with minimum effort. Knowledgeable guides will entertain you with the most interesting stories about Presidents, Congress, memorials, and parks. Comfortable bikes and a smooth tour route(路线) make cycling between the sites fun and relaxing.

    Washington Capital Sites at Night Bicycle Tour

    Duration: 3 hours(7miles)

    Join a small group bike tour for an evening of exploration in the heart of Washington, D.C. Get up close to the monuments and memorials as you bike the sites of Capitol Hill and the National Mall. Frequent stops are made for photo taking as your guide offers unique facts and history. Tour includes bike, helmet, and bottled water. All riders are equipped with reflective vests and safety lights.

    My name is Kobus Vermeulen. On February 16, 2015, I was one of five South Africans among the 100 people selected by Mars One to begin training to live on the Red Planet. The Dutch not-for-profit's aim is simple: build a human colony (殖民地) on Mars. Since I have begun this journey, the one question that people ask me most is why I want to leave a good planet for wasteland. Here is why.

    I have been interested in Mars since I was a child, and I always thought that if I had the opportunity to leave the planet, I would take it. So the why begins with a child's dream.

    However, as I grew, so did the why. In my eyes, since the 1970s the public has stopped trying to learn more about space. We've put our dream aside. We're satisfied with getting our dose (一份) of the future from sci-fi movies and comic books. And so the first part of my motivation (动机) is to get people thinking about space travel and the colonization (殖民化) of other planets in real terms again instead of just as sci-fi visions of the future.

    If we want that future, the truth is that we have to build it, and anything worth doing comes with risks. Somebody has to take the risks, and I, along with thousands of other people, am willing to take them.

    But it goes deeper than that. If the task of Mars One is even partially (部分地) successful, it will encourage a new generation of scientists and engineers that will build us an even better future.

    Without a dream, there is no reason to build those things. The public that does not try to understand science and technology does not choose good leaders. Leaders who don't care for science and technology do not make budgets (预算) for it. Besides, without the money, the dream dies. Projects like Mars One are like a focusing lens (聚焦透镜) for dreams. It is an opportunity to change hearts and minds at the grassroots level.

Dear Alcohol,

    You've been around forever. I can remember all the pain you've caused for me.

    Do you remember the night you almost took my father's life? I do. He loves you. Sometimes I think he loves you more than he loves me. He's addicted to you, to the way you promise to rid him of his problems only to cause more of them. You just sat back and laughed as his car went spinning through the street, crashing into two other cars. He wasn't the only one hurt by you that night.

    Do you remember the night of my first high school party? You were there. My friends were intrigued by you. They treated you as if they were never going to see you again, drinking all of you that they could. I spent two hours that night helping my friends who had fallen completely. "I'm so embarrassed," they said as I held their hair back so that they could vomit. "I'm sorry," they said when I called taxies for them, walking them out and paying the driver in advance. "This won't happen again," they said as they were sent to the hospital to have their stomachs pumped. Two 15-year-old girls slept in hospital beds that night thanks to you.

    Do you remember the night when you took advantage of my 17-year-old neighbor who had to drive to pick up his sister from her dance lessons? Do you know how we all felt when he hit another car and killed the two people in the other car? He died the next morning too. His sister walked home from her dance lesson, and passed police cars and a crowd of people gathering on the sidewalk just two blocks away from the dance studio. She didn't realize her brother was in the midst of it all. She never saw him again. And it's all your fault.

    I wish you'd walk out of my life forever. I don't want anything to do with you. Look at all the pain you've caused. Sure, you've made people happy too from time to time. But the damage you've caused in the lives of millions is inexcusable. Stop luring (引诱) in the people I love. Stop hurting me, please.

Sincerely,

Me