【简答题】一个袋中装有8个大小质地相同的球,其中4个红球、4个白球,现从中任意取出四个球,设X为取得红球的个数. (1)求X的分布列; (2)若摸出4个都是红球记5分,摸出3个红球记4分,否则记2分.求得分的期望.
【简答题】一个袋中装有8个大小质地相同的球,其中4个红球、4个白球,现从中任意取出四个球,设 为取得红球的个数. (1)求 的分布列; (2)若摸出4个都是红球记5分,摸出3个红球记4分,否则记2分.求得分的期望.
【单选题】下列税法要素中,可以作为区别不同税种的重要标志的是
【单选题】What is the meaning of the sentence "There are times when I want to kill Sarah...but I'd kill for her all the time"?
A.
Sometimes I want to kill Sarah. Sometimes I want to kill others.
B.
I always like to help Sarah although sometimes I have fights with her.
C.
Sometimes I want to kill Sarah. But I want to kill others all the time.
D.
I always hate Sarah. So I want to kill her all the time.
【单选题】袋中装有1个红球4个白球,任意取出2个球,若以X表示其中的红球数,以Y表示其中的白球数,则二维随机变量(X, Y)关于Y的边缘分布律为
A.
P { Y =1}=0.6, P { Y =2}=0.4
B.
P { Y =1}=0.4, P { Y =2}=0.6
C.
P { Y =1}=0.2, P { Y =2}=0.8
D.
P { Y =0}=0.2, P { Y =1}=0.2, P { Y =2}=0.6
【简答题】Yes. That’s all ______ I want to take.此题出自2015年福建三明市中考英语真题及答案,2015年福建三明中考英语试题及答案 —Is that all? —Yes. That’s all ______ I want to take. A.which B.that C.who D.whose
【简答题】你已经上大学了,应该学会独立自主。(now that, learn,independent)
【单选题】下列税法要素中,可以作为区别不同税种的重要标志的是
【单选题】I want to walk to Qianmen Street to buy something, _______ I think walking all the way is tiring.