Molecules in million‑year‑old fossils show a warmer, wetter past ^{CEFR A1}

Difficult words

• molecule — A very small piece of a substance.

  molecules
• fossil — A preserved part of an old animal or plant.

  fossil bones, fossils
• metabolism — The chemical processes inside a living body.
• environment — The natural place where plants and animals live.

  environments
• infection — When germs cause illness in the body.
• researcher — A person who studies or tests things.

  Researchers

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