Lightning is an electric current. Within a thundercloud way up in the sky, many small bits of ice (frozen raindrops) bump into each other as they move around in the air. All of those collisions create an electric charge. After a while, the whole cloud fills up with electrical charges. The positive charges or protons form at the top of the cloud and the negative charges or electrons form at the bottom of the cloud. Since opposites attract, that causes a positive charge to build up on the ground beneath the cloud. The grounds electrical charge concentrates around anything that sticks up, such as mountains, people, or single trees. The charge coming up from these points eventually connects with a charge reaching down from the clouds and - zap - lightning strikes!
Germany and Japan favored military solutions more than the United States did. I think the militaristic nations felt they had more to prove on the world stage. For Germans, rearmament became a point of national pride. For the Japanese, imperialism played a similar role. By contrast, Americans entered World War I reluctantly, and they remained reluctant to enter World War II until the bombing of Pearl Harbor left them with few alternatives.
The sentence "The purpose of this workshop is _____ new employees with all the necessary information" requires an infinitive to be completed. An infinitive is the basic form of a verb, without an inflection binding it to a particular subject or tense. "To provide" is an infinitive, and thus completes the sentence properly.