Water's main function in the human body is for respiration. And children are born "when the wall of the uterus expands so the baby can breathe and can get out".
So wrote some 14-year-olds in last year's key stage 3 tests, in English, maths and science, this week's annual standards reports from the Qualifications and Curriculum Authority say.
As usual, answers in all three subjects varied widely in quality. The controversial Shakespeare writing test, in which pupils did not have to demonstrate knowledge of the Bard's work, attracted a particularly diverse response.
Having read an extract from Henry V, youngsters were asked to come up with an inspiring speech, perhaps as given by a captain of a sports club.
One pupil, who achieved a level 7, imagined giving a rousing address, citing the Battle of Agincourt, to a football team about to face a rival squad in a cup match. The piece featured detailed tactical advice for individual team members.
The reports are used every year to highlight areas in which pupils are improving and those where teaching could be better.