在“夫伤于寒,有即病者焉,有不即病者焉”中,“于”的意义是:()
A.被
B.从
C.对
D.比
参考答案:A
14.Jim insisted that the book Mr. Black referred to ________.
A.was worth to be bought
B.was worth buying
C.being worth buying
D.be worth buying
对下列常见密度函数所对应的方差的形式正确的一项是()。
A.两点分布b(1,p)方差np(1-p)
B.超几何分布h(h,N,M)方差n(N-n)/(N-1)•(M/N)(1-(M/N))
C.均匀分布U(a、b)方差((b+a)2/12
D.对数正态分布LN(μ,σ2)方差