问题 选择题
某地举行一次民歌大奖赛,六个省各有一对歌手参加决赛,现要选出4名优胜者则选出的4名选手中恰有且只有两个人是同一省份的歌手的概率为(  )
A.
16
33
B.
33
128
C.
32
33
D.
4
11
答案

由题意知本题是一个古典概型,

试验发生的总事件是从12名选手中选出4个优胜者,共有C124种 结果,

而满足条件的是选出的4名选手中恰有且只有两个人是同一省份的歌手表示从6个省中选一个省,它的两名选手都获奖,同时从余下的10名选手中选一个,再从剩下的4个省中选一个,共有C61C101C41种选法,

∴P=

C16
C110
C14
C412
=
16
33

故选A.

单项选择题

完形填空:下面的短文有l5处空白,请根据短文内容为每处空白确定l个最佳选项。

Obesity(肥胖) Causes Global Warming.

The list of ills attributable to obesity keeps growing: Last week, obese people were accused of causing global warming.

This ______(51)comes from Sheldon Jacobson of the University of Illinois, US, and a doctoral student, Laura McLay. Their study ______(52) how much extra gasoline is needed to haul fat Americans around. The answer, they say, is a billion gallons of gas per year. ______(53)

There has been ______(54) for taxes on junk food in recent years. US economist Martin Schmidt suggests a tax on fast food ______(55)to people’s cars. "We tax cigarettes partly because of their health cost," Schmidt said. "Similarly, leading a lazy life style will end ______(56) costing taxpayers more."

US political scientist Eric Oliver said his first instinct was to laugh at these gas and fast food arguments. But such ______(57) are getting attention.

At the US Obesity Society's annual meeting, one person ______(58) obesity with car accident deaths, and another correlated obesity with suicides. No one asked whether there was really a cause-and-effect relationship. " The funny thing was that everyone took it ______(59)." Oliver said.

In a 1960s study, children were ______(60) drawings of children with disabilities and without them, and a drawing of an obese child. They were asked ______(61) they would want for a friend? The obese child was picked last.Three researchers recently repeated the study ______(62) college students. Once again, ______(63) no one, not even obese people, liked the obese person. " Obesity was stigmatized." the researchers said.

But, researchers say, getting______ (64) is not like quitting smoking. People struggle to stop smoking, and, in the end, many succeed. Obesity is different. Science has shown that they have limited personal control over their weight Genes also______ (65) a part.

59.(单项选择题)      

A.seriously

B.well

C.hard

D.greatly

单项选择题