_____ name is Lily. _____ am twelve. [ ]
A. I, My
B. I, I
C. My, I
D. My, My
答案:C
人体之气的生成之源是
A.心
B.肝
C.脾胃
D.肺
E.肾
设随机变量X的数学期望E(X)=μ,方差D(X)=σ2,则由切比雪夫(Chebyshev)不等式,有P|X-μ|≥3σ≤______.