你能帮帮他们吗
精彩回答
We all understand that learning a foreign language ______ time and efforts.
10个月前
Henry broke the window .I’ll ask him why __________ .
1年前
在同一平面直角坐标系中,一次函数y=ax+b和二次函数y=ax2+bx的图象可能为( )
1年前
Lily succeeded,for she had made a great________and got over plenty of difficulties. [ ]
1年前
设随机变量X~U[0,1],Y=X^2-4X+1,求: (1)随机变量Y的概率密度; (2)EY和DY; (3)X与Y的相关系数.
1年前