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One _________ is one billionth of a metre.
Cylinders made of carbon.
The wounded climber was helped to ______.
Compounds that make petrol and diesel.
Burning diesel makes ____________.
______ is the fourth most abundant element in the universe.
_______ is neither acid nor alkaline.
Water is two parts ________ and one part oxygen.
This truck's engine runs on diesel ____.
Living organisms contain many cells.
Reduces energy required for a chemical reaction to take place.
Converts harmful substances in the engine to less harmful ones.
You'll often find ______ plants near native populations.