填空题
- A．occurs most infrequently
- B．is shifted sideways by strong winds
- C．is often hidden from our view
- D．is equipped with a good knowledge of various forms of lightning
E is estimated at 20 millions a year
F is positively charged
填空题
In most cases of cloud-to-ground lightning the ground's surface______
填空题
One form of lightning that ______ is ball lightning.
填空题
Cloud lightning looks like a ribbon when its lightning channel______
填空题
Although not fully understanding processes of lightning man______