成组设计方差分析，若处理因素无作用，则理论上有（）
A.F=0
B.F<1
C.F=1
D.F>1
E.F<1.96
参考答案：C
151. The passenger _____ at his watch and found that it was too late when he arrived the railway station.
A．gazed
B．stared
C．glanced
D．Glared
怎样合理安全使用乙炔瓶？
