问题 填空题

现有A、B两枚均匀的小骰子(骰子的每个面上粉笔标有数字1、2、3、4、5、6),若用小柯掷A骰子朝上的数字x、小景掷B骰子朝上的数字y来确定点P(x,y),则他们各掷一次所确定的点P落在已知抛物线y=-x2+5x-2上的概率为______.

答案

列表得:

123456
1(1,1)(1,2)(1,3)(1,4)(1,5)(1,6)
2(2,1)(2,2)(2,3)(2,4)(2,5)(2,6)
3(3,1)(3,2)(3,3)(3,4)(3,5)(3,6)
4(4,1)(4,2)(4,3)(4,4)(4,5)(4,6)
5(5,1)(5,2)(5,3)(5,4)(5,5)(5,6)
6(6,1)(6,2)(6,3)(6,4)(6,5)(6,6)
∵共有36种等可能的结果,点P落在已知抛物线y=-x2+5x-2上的有:(1,2),(2,4),(3,4),(4,2),

∴点P落在已知抛物线y=-x2+5x-2上的概率为:

4
36
=
1
9

阅读理解

In 1901, the citizens of Colorado Springs in the USA decided to collect everyday items and to seal (封住)them in a special box. The box was marked “To be opened after midnight, December 31st, AD 2000”,and was kept in the Colorado College Library.

One hundred years later, on the appointed (约定)day, 300 people gathered to watch the opening of the box. Many in the crowd were the descendants (后代)of people who had placed things inside the box.

When the box was opened after midnight, the things inside the box were in very good condition. There were newspapers, photos, diaries, name cards, family trees, books and lots of letters, including one written by Theodore Roosevelt, who became the President of the USA later that year. One of Roosevelt’s friends lived in Colorado Springs at that time.

Many of the letters were written to their descendants. They describe the hopes that the people of 1901 had for the people of the next century. At that time, Colorado Springs had just a few thousand people. Now nearly half a million people live there.

Colorado College Library has scanned the materials and put them on a website. Cecil Muller, whose grandfather had placed a collection of postcards in the box, said that the time capsule was a great treasure. “This is a wonderful educational resource(资源).  We can learn so much about our history,”he said. “I never knew my grandfather, but now I feel very close to him. ”

小题1:According to the passage, “time capsule” means ______.

A.a collection of clocks and watches

B.a machine for travelling through time

C.a collection of items for people to look at in the future

D.a collection of unwanted items小题2:Many of the letters in the time capsule talked about   .

A.the history of the town

B.the people who lived in the town

C.the politics of the USA

D.people’s hopes for the future小题3:Cecil Muller says that the time capsule ______.

A.helps him to get to know his grandfather

B.is worth a lot of money

C.brings back his memories of his grandfather

D.helps him to remember his younger day

单项选择题 B1型题