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（本小题满分10分） 某省份今年是新课标高考的第一年，某校为了充分了解新课标高考，数学备课组从过去2年的新课标各地模拟卷中挑选出50份试卷进行研究，各地挑选的试卷数如下表所示： 地区 地区A 地区B 地区C 地区D 试卷数 20 15 5 10 （1）从这50份试卷中随机选出2份，求2份试卷选自同一地区的概率； （2）若从C、D两地区挑选出2份试卷进行研究，设挑选出地区C的试卷数为 ，求随机变量 的分布列和数学期望。
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【单选题】Obesity (肥胖): the Scourge (祸害) of the Western World Obesity is rapidly becoming a new scourge of the western world, delegates agreed at the llth European Conference on the issue in Vienna Wednesday to...
A.
250,000,000
B.
1,200,000,000
C.
1,450,000,000
D.
950,000,000
【单选题】Obesity（肥胖）：the scourge（祸害）of the western world Obesity is rapidly becoming a new scourge of the western world，delegates agreed at tile 11th European Conference on the issue in Vienna Wednesday to Sat...
A.
250，000，000
B.
1，200，000，000
C.
1，450，000，000
D.
950，000，000
【单选题】下列属于尾突出体作用的是:1、增强船尾的结构强度;2、保护车叶和舵;3、减少伴流影响;4、改善航行性能
A.
①、②、③、④
B.
②、③、④
C.
①、③、④
D.
①、②、④
【单选题】Obesity : the Scourge of the Western World Obesity is rapidly becoming anew scourge of the western world, delegates agreed at the llth Eu-ropeanConference on the issue in ViennaWednesday to Saturday. ...
A.
250,000,000
B.
1,200,000,000
C.
1,450,000,000
D.
950,000,000
【单选题】In what way is obesity contagious and epidemic?
A.
Social networks let the obesity spread rapidly.
B.
Individuals have genetically determined ranges of weights.
C.
Obesity can easily spread from one to another without any physical contact.
D.
Obesity can spread rapidly and extensively by infection and affecting many individuals in an area or a population at the same time.
【单选题】Obesity Epidemic Ask anyone why there is an obesity epidemic and they will say that it's all down to eating too much and burning too few calories. That is undoubtedly true. But it's also true that we ...
A.
Y
B.
N
C.
NG
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