搜题请搜索小程序“爱下问搜题”
问题 单项选择题

祖父现在的年龄是小明的6倍，过几年之后，祖父的年龄将是小明的5倍，再过几年之后，祖父的年龄将是小明的4倍，请问小明今年多少岁

A．10
B．11
C．12
D．13

答案

参考答案：C

解析： 祖父和小明的年龄差是一个定值，由于祖父现在的年龄是小明的6倍，因此年龄差应该是小明年龄的5倍，即年龄差是5的倍数，同理可得年龄差是4、3的倍数，因此年龄差是60(5、4、3的最小公倍数)的倍数，由常识可知，年龄差就是60，小明今年应该是60÷5=12岁。

单项选择题

Like all the huge metropolises of the world, there are lots of diversions both outdoors and indoors in Chicago. The Art Institute of Chicago has one of the world’s (1) art collections, including more French Impressionist paintings than even in the Paris Louvre itself. The Field Museum of Natural History and the Museum of Science and Industry are also great historical and cultural treasure houses to (2) as well as entertain children and adults (3) In the Field Museum one comes (4) a surprisingly big collection of Chinese exhibits from the ancient (5) to the early century. The Sears Tower and the Buckingham Fountain are the pride of the Chicagoans; (6) having 110 storeys is said to be the highest tower in the world and the (7) is the largest fountain in the United States. Lake Michigan is for yachting in summer time, (8) the highlights of Chicago life all the year round are concerts, operas and plays (9) by the city’s orchestra, opera houses and theatres. In summer, especially around the Independence Day, July 4th, many festivals and fairs are given outdoors, which, (10) crowds and crowds of people, with their parades, fireworks, (11) concerts, water-skiing and good foods.

But with all its attractions and beautiful spots Chicago is also a city (12) for crimes. All the dwelling houses are (13) with three doors and visitors have to speak through microphone (14) in the wall to the residents before they can get admitted. In the streets there are white-color telephones. When one finds oneself (15) , he needs only to knock the receiver (16) the hook and the next instant the police will (17) . If one does not drive a car, it may well be dangerous for him or her to go out alone in the evening. At first I did not take this warning seriously. (18) , my two encounters with the Black people (19) dusk in the neighborhood were so unpleasant and frightening that I have (20) shut myself evenings in my room, in almost all studying, imposing a curfew on myself.

3（）

A.alike

B.both

C.like

D.either
查看答案
问答题 简答题

制粉设备检修工作前，必须采取哪些安全措施？
查看答案