题目

甲、乙两城相距480km，货车以每小时60km的速度从甲城开往乙城，2小时后，客车才从乙城开往甲城，经过2.5 小时，两车相遇，客车每小时行多少千米？ 答案：解：设客车每小时行x千米， 2.5x+（2+2.5）×60=4802.5x+4.5×60=480 2.5x+270=480 2.5x+270-270=480-270 2.5x=210 2.5x÷2.5=210÷2.5 x=84 答：客车每小时行84千米。Not all inventions are made by scientists. Kids can also make history with their inventions.The state flag of Alaska was designed by 13-year-old Bennie Benson in 1926. His design was chosen from a flag-designing competition. It became the official flag in 1959. Bennie won a ＄1,000 scholarship（奖学金）and a watch.Frank Epperson invented the Popsicle in 1905 when he was only 11 years old. It was called the Epsicle at that time. Frank left his drink outside the door overnight with a stick（木棒）in it. That night the temperature dropped and everything was frozen including Frank’s drink. That didn’t stop him from tasting it, so today we have Popsicles to eat.In 1642 Blaise Pascal designed the first counting machine when he was 18.The machine was for his father, a tax collector, to make his job easier. Blaise named it “the Pasealine”. He made about 50 of them, but nobody was interested in it. People thought it would take jobs away from them. 300 years went by, and the calculator（计算器）finally became a success. In 1968, the programm?ng language（程序设计语言）, PASCAL, was named after him.1. How old was Bennie Benson when he designed the flag?A.13. B. 26. C. 46. D. 59.2. What does the underlined word “Popsicle” mean in Chinese?A.凉茶 B.美味 C.冰柜 D.棒冰3. Why did Blaise Pascal invent the calculator?A. Because he wanted to use it in a test.B. Because he wanted to make his father’s job easier.C. Because he wanted to sell it for money.D. Because he wanted to know how much money he should give to sellers.4.Why were people not interested in “the Pasealine” at first?A. Because people thought it could make them lose jobs.B. Because they thought it was useless.C. Because it cost a lot.D. Because there was no programming language then.5.This passage mainly tells us about_______.A. several useful inventionsB. several inventions by kidsC. how to make historyD. how to become a successful inventor