题目

公园里，一条宽2米的小路围绕着圆形水池的一周，水池的直径是20米，小路的占地面积是多少平方米？ 答案：解：20÷2=10（米 ） 10+2=12（米 ） 3.14×（12×12 -10×10）=3.14×44＝138.16（平方米） 答：小路的占地面积是138.16平方米。 阅读理解 　　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(心理学家)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(因素)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(大方的)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 half were instructed to repeat the orders and preferences back to the customers．Rick van Baaren then compared their take-home．The results were clear－it pays to mimic your customer．The copycat 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 may be limited by his bill．After research on the 1000 tips left for waiters, cab drivers, hair stylists, they found tip percentages in three areas dropped as customers’ bills went up．In fact, tip percentages appear to plateau(达到稳定水平)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 cab driver 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．” (1) How many factors affecting the customers’ tipping are mentioned in the passage? [　　] A． 2． B． 1． C． 3． D． 4． (2) According to the passage, a customer gives the cab driver a tip for ________． [　　] A． driver’s politeness B． driver’s mimicry C． driver’s attitudes D． being there (3) According to the passage, which of the following will be likely to show the right change of the tip percentages? [　　] A． B． C． D． (4) According to the passage, we know the writer seems to ________． [　　] A． oppose Mr．Green’s idea about tipping B． think part of Mr．Green’s explanation is reasonable C． give his generous tip to the waiters very often D． support the opinions of Mr．Green and Rick van Baaren about tipping