In this task, you are given a word. You should respond with a valid sentence which contains the given word. Make sure that the sentence is grammatically correct. You may use the word in a different tense than is given. For example, you may use the word 'ended' in the output where the given input word is 'end'.

[EX Q]: reaction
[EX A]: When I last tried to eat strawberries I had a terrible allergic reaction.

[EX Q]: principle
[EX A]: The principle of the internal combustion engine.

[EX Q]: formula
[EX A]:
He gave us a general formula for attacking polynomials.