React and Replying

verb

• Show a response or a reaction to something.
  • synonyms: respond
• Act against or in opposition to.
  • usage: "She reacts negatively to everything I say"
  • synonyms: oppose
• Undergo a chemical reaction; react with another substance under certain conditions.
  • usage: "The hydrogen and the oxygen react"

• (v.t.) To act or perform a second time; to do over again; as, to react a play; the same scenes were reacted at Rome.
• (v.i.) To act upon each other; to exercise a reciprocal or a reverse effect, as two or more chemical agents; to act in opposition.
• (v.i.) To return an impulse or impression; to resist the action of another body by an opposite force; as, every body reacts on the body that impels it from its natural state.