對價，承諾被允諾、提供或做成的事物，它能使一項協(xié)議成為具有法律效力的契約 Something promised, given, or done that has the effect of making an agreement a legally enforceable contract.
這藥沒有效力。 The drug was of no effect.
反對黨領袖答應提供一個有效力的政治體制。 The leader of the opposition is promising to provide effective government.
彈藥學關于彈藥的發(fā)射、飛行、和效力的研究 The study of the firing, flight, and effects of ammunition.
