造成3～9人死亡的生产安全事故属于______。
A．一般事故 B．重大事故C．较大事故 D．特别重大事故
参考答案：C
In some countries,_____ are called "public schools" are not owned by the state.
A．that
B．which
C．as
D．what
某资料服从对数正态分布，描述其集中趋势最合适的指标是
A．均数B．几何均数C．中位数D．标准差E．百分位数
