An onion carries the means of its own defence in two separate compar. The kn breaks th open toge, an enz meets t compound i acts o, and t reaction thr off a gas light enough to drift upward. Tears are the result of the gas dissolving in the film of water across the eye, where it turns faintly acidic and the eye flushes it away. Chilling the onion slows the enzyme, and cutting beside running water carries the gas off before it can rise.

Type only the missing letters. Each box is one letter, and the number of boxes matches the letters that are missing.