Найдите в нем и выпишите следующие грамматические формы:
а) –ing формы;
б) модальные глаголы и их эквиваленты;
в) сравнительные степени прилагательных;
г) видо-временные формы глаголов-сказуемых.

HOW FIRE WAS DISCOVERED

The very earliest men knew about fire. It flashed at them from volcanoes, in
lightning and in forest fires. At first fire was the thing that only frightened them. Then
they found that fire could be useful and, to a certain extent, kept under control.
Early man used fire for cooking and hardening his weapons. The precious fire
was guarded, watched and constantly fed. Moving from place to place people carried
fire with them. If it went out, they had to wait for a forest fire or for a lightning that
struck some tree. Sometimes they got it from another tribe they met.
So we can’t name a certain man who discovered fire and don’t know for sure
the way how it happened. Some people think that man learnt about fire when he saw
lightning setting fire to a dead tree. Others consider that man saw fire started by rubbing
together two branches of a tree and then tried to initiate this process himself. After
man had learnt how to get fire he came to know its benefits and started using it
widely.​