Notes on coal and petroleum

The book gives a passage to practise on, about coal and petroleum. Its main points:

• The energy in coal and petroleum first came from the sun.
• Most of it was laid down 200 to 600 million years ago, when the climate was tropical.
• Swamp forests and seas full of tiny living things died. Mud covered some of their remains, so they did not fully rot.
• Layer upon layer of sediment pressed down on them over millions of years, turning them into rock, and making coal and petroleum.
• Coal formed mostly from giant fern-like plants. Conditions today do not allow much new coal to form.

A useful trick in note-making is to turn verbs into nouns, which makes points shorter. 'The sediments hardened into rock' becomes 'hardening of sediment into rock'.

Then combine and group related points under headings (such as 'Origin of coal' and 'Origin of petroleum'), and number them.