A

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 the 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 hour

    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. Knowledge guides will entertain you with the most interesting stories about Presidents. Congress, memories, 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 hour (7 miles)

    Join a small group hike 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 rides are equipped with reflective vests and safety lights.

    Technology offers conveniences such as opening the garage door from your car or changing the television station without touching the TV.

    Now one American company is offering its employees a new convenience: a microchip implanted in their hands. Employees who have these chips can do all kinds of things just by waving their hands. Three Square Market is offering to implant microchips in all of their employees for free. Each chip costs $300 and Three Square Market will pay for the chip. Employees can volunteer to have the chips implanted in their hands. About 50 out of 80 employees have chosen to do so. The president of the company, his wife and their children are also getting chips implanted in their hands.

    The chip is about the size of a grain of rice. Implanting the chip only takes about a second and is said to hurt only very briefly. The chips go under the skin between the thumb and forefinger. With a chip in the hand, a person can enter the office building, buy food, sign into computers and more, simply by waving that hand near a scanner. The chips will be also used to identify employees. Employees who want convenience, but do not want to have a microchip implanted under their skin, can wear a wristband or a ring with a chip instead. They can perform the same tasks with a wave of their hands as if they had an implanted chip.

    Three Square Market is the first company in the United States to offer to implant chips in its employees. Epicenter, a company in Sweden, has been implanting chips in its employees for a while.

    Three Square Market says the chip cannot track the employees. The company says scanners can read the chips only when they are within a few inches of them. “The chips protect against identity theft, similar to credit cards.” The U.S. Food and Drug Administration approved the chips back in 2004, so they should be safe for humans, according to the company.

    In the future, people with the chips may be able to do more with them, even outside the office. Todd Westby is Chief Executive Officer of Three Square Market. He says, “Eventually, this technology will become standardized allowing you to use this as your passport, public transit, all purchasing opportunities, etc.”

下面每个表格中的四个数都是按相同规律填写的：

根据此规律确定x的值为（　　）

下列用电器中，主要把电能转化为机械能的是(  )