. --- The company spent thousands of dollars to promote its new product.

--- They _____: the world itself was more than ready to buy.

A．shouldn’t have bothered

B．needn't have bothered

C．couldn’t have bothered

D．mustn’t have bothered

隔室的设置与铠装型一样，但隔室的隔板用绝缘材料，结构紧凑是什么金属封闭开关设备特点？（）

A.间隔型

B.铠装型

C.固定式

D.移开式（手车式）