"there was a chemical reaction of the lime with the ground water"
"his reaction to the news was to start planning what to do"
"a bad reaction to the medicine" "his responses have slowed with age"
"every action has an equal and opposite reaction"
"he was pleased by the audience's reaction to his performance" "John feared his mother's reaction when she saw the broken lamp"
"the forces of reaction carried the election"
"his style of painting was a reaction against cubism"