一个多边形除了一个内角外,其余各内角之和为1680°,那么这个多边形的边数为_
题型：填空题
问题：
一个多边形除了一个内角外,其余各内角之和为1680°,那么这个多边形的边数为________.
题型：填空题
| 阅读理解。 阅读下列应用文及相关信息，并按照要求匹配信息。 下面是几条与节日有关的报道，首先请阅读这些报道的标题和插图：
以下是这些报道的简要内容介绍，请配对它们的标题。 1. Where did this most popular day for couples come from? And how does it come into beings, year after year? Noel Lenski, professor of the University of Colorado, said the lovers' holiday traces its roots to raucous annual Roman festivals held every year on February 15 and remained wildly popular well into the fifth century A.D. 2. The first Earth Day in 1970 was a raucous, radical teach-in that helped spur clean-air, clean-water, and endangered species legislation in the United States. Now, 40 years later, Earth Day is every day, as the saying goes. The thing is, it's also everyday - environmentalism has become a routine with greenness as much a marketing tactic as a moral pursuit. 3. Some 242 million turkeys were raised in the U.S. in 2010 for slaughter, according to the U.S. Department of Agriculture's National Agricultural Statistics Service. Last year's birds were worth about U.S. $3.6 billion. Before the big dinner, debunk the myths, we need to know that the first "real" U.S. Thanksgiving wasn't until the 1800s and get to the roots of Thanksgiving 2010. 4. Father's Day traditionally takes a backseat to Mother's Day, and, for the most part, dads are cool with that, experts say. Nevertheless, as traditional roles around the house gradually change, fathers are gaining more attention on their special day, at least as measured in the monetary value of gifts estimated to be given on June 19, 2011, when the holiday will be celebrated in dozens of countries. 5. Cookouts, fireworks, and, of course, a chance to wish Uncle Sam a big "happy birthday" -the day means summer in full swing across the United States and beyond. Besides the founders of the US, Fireworks, first authorized by Congress in 1777, are another legacy. More than 14,000 fireworks displays light up U.S. skies each year. |
