【单选题】听力原文:M: Would you pass me the sports section please? W: Sure, if you give me the classified ads and local-news section. What are the speakers doing?
C.
Writing up local news.
D.
Putting up advertisements.
【多选题】直流电机换向时,火花产生的原因有( )原因。
【简答题】设随机变量X的分布律为 X 0 1 2 3 P 0.1 A 0.3 0.2 求
【简答题】设随机变量X的分布律为P{X=k}=1/4(k=1,2,3,4),函数Y=eosπX.求二维随机变量(X,Y)的联合分布律.
【简答题】设随机变量X的分布律为 ,求概率P{X 2 ≥1}.
【单选题】设随机变量X的分布律为 X -2 0 2 P 0.3 0.2 0.5 则Y=|X|的分布列为( )
C.
X -2 0 2 P 0.09 0.04 0.25
【多选题】Bronze ware was a unique national treasure because of ( )
B.
classical decorative ornamentation
D.
wealth of inscriptions
【单选题】听力原文:M: Would you pass me the sports section,please? W: Sure, if you give me the classified ads and local news section. Q: What are the speakers doing? (19)
B.
Writing up local news.
D.
Putting up advertisements.
【单选题】Passage Two
A.
The difference between classical music and rock music.
B.
Why classical music is popular with math students.
C.
The effects of music on the results of math tests.
D.
How to improve your reasoning ability.
【简答题】设随机变量X的分布律为 X 0 1 2 3 P 0.1 A 0.3 0.2 求(1)常数A;(2)P(0.5≤X<2).