1787年费城会议制定的《美利坚合众国宪法》规定：合众国不得授予贵族爵位。这反映了美国宪法的主要原则是

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    In England nobody under eighteen years old is allowed to drink in a bar（酒吧）. Mr. Thompson often went to a bar near his house. But he never took his son, Tom, because he was too young. Then when Tom had his eighteenth birthday, Mr. Thompson took him to his usual bar for the first time. They drank for an hour. Tom drank a bit. Then Mr. Thompson said to his son, "Now, Tom, I want to teach you a useful lesson. How do you know when you've had enough? Well, I'll tell you. Did you see those two lights at the end of the bar? When they seem to become four, you've had enough and should go home."

    "But, dad, "said Tom, "I can only see one light at the end of the bar."

把一个正六棱柱如图1摆放，光线由上向下照射此正六棱柱时的正投影是（  ）

欧洲西部有一个世界上最有影响的区域性国际组织，简称是（   ）