A. alive. B. really you. C. bacteria.
A. really helpful. B. bad for humans. C. neither good or bad.
A. fight diseases. B. provide energy. C. digest food.
A. 7 million B. 7 trillion C. 7 octillion
A. tiny cubes. B. not used. C. empty space.
A. hair. B. ears. C. eyelashes.
A. 3 millimetres long. B. a third of a millimetre long. C. 0.03 millimetres long.
A. dead skin. B. your eyelashes. C. tiny insects.
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