【简答题】Translation: 随函附上我英文老师的推荐函。
【简答题】Thomas was a real friend, for he advised me as well as (help)____________me with my Arabic.
【单选题】关于二维随机变量的联合分布与边缘分布关系,下列选项不正确的是( )
A.
无论X与Y是否独立,联合分布可以由边缘分布来确定。
B.
无论X与Y是否独立,边缘分布可以由联合分布来确定 。
C.
若X与Y独立时,联合分布可以由边缘分布来决定。
D.
无论X与Y是否独立,边缘分布否都可以联合分布确定。
【单选题】Thomas was a real friend, for he advised me as well as ___________ me with my Arabic. [ ]