判断题-|||-设X1,X2,···,Xn是来自总体 sim N-|||-(μ,σ^2)的样本,且σ^2未知,用样本检验假设-|||-_(0):mu =mu O 时,采用的统计量是 dfrac (sqrt {n)cdot overrightarrow (X)}(S)-|||-()