概括大意与完成句子
Lightning can occur within a cloud, between clouds, or between clouds and the ground. The first variety, intra-cloud lightning, is the most frequent but is often hidden from our view. Cloud-to-ground lightning, making up about 20 percent of lightning discharges, is what we usually see. Lightning comes in several forms, including sheet, ribbon, and ball. Intra-cloud lightning can illuminate a cloud so it looks like a white sheet, hence its name. When cloud-to-ground lightning occurs during strong winds, they can shift the lightning channel sideways, so it looks like a ribbon. The average lightning strike is more than 3 miles long and can travel at a tenth of the speed of light. Ball lightning, the rarest and most mysterious form, derives its name from the small luminous ball that appears near the impact point, moves horizontally, and lasts for several seconds.
The main idea of this paragraph is ________.
A、How does Lighting Happen
B、Types of Lighting
C、Lightning Comes in Several Forms
D、Cause of Lighting
【正确答案】 B
【答案解析】 整个段落的内容介绍了闪电的三种类型：云层内部闪电，云层与云层之间的闪电，云层与地面之间的闪电，此外还介绍了闪电可有片状、带状和球状。因此选择B 闪电的类型。
