In the following passage some words have been deleted. Read the passage carefully and select the most appropriate option to fill in each blank.

Fire is a significant factor in human (1)________. The Stone Age man was the first to discover and use fire, which provided him (2) ________ and a means to cook food. Initially, he produced fire by rubbing two stones, and the (3) ________ between two stones generated fire. But this process was very (4) ________ and he wanted to discover a less laborious way of producing fire. For this he had to first preserve the fire. He discovered a fire band and carried it everywhere. This discovery led to the invention of torches and lamps that could be used for (5) ________, and preserving flame. So, we can say that fire is an accidental invention.