The conference has been held to discuss the effects of tourism ________the wildlife in the area.

A．in

B．on

C．at

D．with

若固体电介质被击穿的时间很短、又无明显的温升，可判断是（）。

A.电化学击穿

B.热击穿

C.电击穿

D.各类击穿都有