序幕先于較重要部分的介紹性表演，事件或行動(dòng)；開(kāi)端或序
An introductory performance, event, or action preceding a more important one; a preliminary or preface.
指實(shí)現后臺處理。所謂后臺處理是指非聯(lián)機處理，或者說(shuō)不是直接和計算機連接起來(lái)而進(jìn)行聯(lián)機操作。優(yōu)先級高的程序先于特定的后臺作業(yè)執行。
Performing background processing which is not on-line or directly connected to the computer for on-line operation. High priority programs take precedence over specific background jobs.
約翰一直領(lǐng)先于其他賽手，并最后贏(yíng)得冠軍。
John kept ahead of the other runners and won at last.
