You're out to dinner. The food is delicious and the service is fine. You decide to leave a big fat tip. Why? The answer may not be as simple as you think.

    Tipping, psychologists have found, is not just about service. Instead, studies have shown that tipping can be affected by psychological reactions to a series of different factors from the waiter's choice of words, to how they carry themselves while taking orders, to the bill's total. Even how much waiters remind customers of themselves can determine how much change they pocket by the end of the night.

    “Studies before have shown that mimicry(模仿) brings into positive feelings for the mimicker,” wrote Rick van Baaren, a social psychology professor. “These studies show that people who are being mimicked become more generous toward the person who mimics them.”

    So Rick van Baaren divided 59 waiters into two groups. He requested that half serve with a phrase such as. “ Coming up !” Those in the other hall were instructed to repeat the orders and preferences back to the customers. Rick van Baaren then compared their take-home pay. 'The results were clear—it pays to mimic your customer. The copycat(模仿者) waiters earned almost double the amount of tips to the other group.

    Leonard Green and Joel Myerson, psychologists at Washington University in St. Louis, found the generosity of a tipper maybe limited by his bill. After research on the 1,000 tips left for waiters, cabdrivers, hair stylists, they found tip percentages in these three areas dropped as customers' bills went up. In fact, tip percentages appear to plateau(稳定期) when bills topped $100 and a bill for $200 made the worker gain no bigger percentage tip than a bill for $100.

    “That's also a point of tipping,” Green says. “You have to give a little extra to the cabdriver for being there to pick you up and something to the waiter for being there to serve you. If they weren't there, you'd never get any service. So part of the idea of a tip is for just being there.”

    Philadelphia, Pennsylvania w America's fifth largest city. Once a major American colonial city, it is the home of America's first library, its first hospital, and its first zoo. Now it is also the first US city to be named a World Heritage City. On November 6, 2015. Philadelphia joined more than 260 other cities that have been recognized for their influence on the world. These cities include Paris, France Florence, Italy and Cairo Egypt.

    "Today marks the start of a new and exciting chapter in the history of Philadelphia" remarked Philadelphia Mayor Michael Nutter when the announcement was made. “As a World Heritage City. Philadelphia is being officially recognized on the global stage for its wealth of contributions to the world. ”

    To be named a World Heritage City, a city be home to a UNESCO World Heritage site are selected for their universal value and significance. For Philadelphia, the site is Independence Hall.

    Independence Hall is where two of the most important documents, approved in US history - the Declaration of Independence and the US Constitution-were adopted. The Declaration of Independence, approved on July 4 1776, united the 13 former British colonies and declared them independent from British rule. The US constitution, signed in 1787, established the American democratic system of government. Democracy is a system of government in which the people elect their leaders. The Constitution later spelled out basic freedoms American citizens have.

    Philadelphia Deputy Mayor Alan Greenberger says the city's selection as a World Heritage City also reflects ta its educational, cultural, and economic achievements. The city is home to dozens of colleges and universities, and many museums, such as the Philadelphia Museum of Art.“Philadelphia has rightfully earned its place as one of the greatest cities in the world.” Greenberger says.

    Have you heard about "Survival Holidays"? It is for children to go into the lonely place for exciting activities. Now about 1,100 companies are allowed to take children into the great outdoors without their parents.

    The reason why people like "Survival Holidays" is that they think being close to nature is good for children. Many children in big cities spend all time watching TV and playing computer games. "Survival Holidays" gives them an important change.

    Is "Survival Holidays" a wonderful idea? Maybe it is. Children need more free time to play. They need to be left on their own, without adults disturbing (干扰) them. Parents care too much about their children. They like to see the children being busy with activities that are controlled (控制) by adults, which causes many problems. Children don't know what to do when they are in danger. Even something like crossing a small river seems to be a hard challenge. Children are not comfortable with danger. Even slight danger like getting their feet wet or falling down seems very terrible to them.

    Many people think the survival activities are good for children. Even years later, they will still remember what they have learned. Some have learned to stay calm in dangerous times. Some have learned how to keep safe. Others have learned how to work in a team. All these skills will help them a lot in their lives.

    You can relax if remembering everything isn't your strong suit. Recent research makes the case that being forgetful can be a strength—in fact, selective memory can even be a sign of stronger intelligence.

    Traditional research on memory has focused on the advantages of remembering everything. But looking through years of recent memory data, researchers found that the neurobiology of forgetting can be just as important to our decision-making as what our minds choose to remember.

    Making intelligent decisions doesn't mean you need to have all the information at hand. It just means you need to hold onto the most valuable information. And that means clearing up space in your memory palace for the most up-to-date information on clients and situations. Our brains do this by creating new neurons(神经元）in our  hippocampus, which have the power to overwrite(重写)existing memories that are influencing our decision-making.

    If you want to increase the number of new neurons in our brain's learning region, try exercising. Some aerobic exercise like jogging, power walking and swimming has been found to increase the number of neurons making important connections in our brains.

    When we forget the names of certain clients or details about old jobs，the brain is making a choice that these details don't matter. Although too much forgetfulness can be a cause for concern, the occasional lost detail can be a sign of a perfectly healthy memory system. The researchers found that our brains facilitate decision-making by stopping us from focusing too much on unimportant past details. Instead，the brain helps us remember the most important part of a conversation.

    We can get blamed for being absent-minded when we forget past events in perfect detail. These findings show us that total recall(记忆)can be overvalued. Our brains are working smarter when they aim to remember the right stories, not every story.

Washington, D.C. Bicycle Tours

Cherry Blossom Bike Tour in Washington, D.C.

    Duration Tour

    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 — 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.

    Taking your pulse during physical activity allows you to measure how hard you are exercising. You should exercise to stay within your target heart range.

    Increasing your heart rate is a key part of exercise but it is important that your heart rate is not too high or too low. If you are a beginner, you should also be able to breathe comfortably while exercising. This will ensure that you are exercising at a level that is safe and effective for your body.

    The chart below illustrates target heart rate ranges for exercise based on the maximal heart rate for selected ages. Here are the steps for using the chart: