削弱树势的修剪方法为（），（）。

试述滴虫性 * * 炎的诊断依据。

在健康保险中，保险人承担的具体补偿或给付责任是指( )导致伤害时发生的费用或损失。

A．投保人因疾病或意外事故

B．受益人因疾病或意外事故

C．被保险人因疾病或意外事故

D．被保险人因疾病或年老

I was on the highway when this car went past followed by a police car. They ______ at the speed of

150 kilometers an hour at least.   [      ]

A. should have been driving              

B. must have been driving

C. could have driven                    

D. would have driven

对总数为N的一批零件抽取一个容量为30的样本，若每个零件被抽到的概率为0．25，则N的值为（）。

A．120

B．200

C．150

D．100

E．180

边塞诗派