She was now in the second year of active munitions production after long covert preparations. 她在長期暗中準備之後，就積極製造軍械，到現在已是第二個年頭了。
The study presented here is the first step in a program aimed at reducing significantly the background count rate of NaI scintillation units. 這裡程序第一步的學習是為了顯著的減少非地址指令傳送單元的暗中統計率。
Cumming tittered in the background. 卡明在背地裡傻笑。
A lie is plump in private but lean in public. 謊言在背地裡很猖獗，在公眾場合就萎縮。
The choic chanted in the background. 唱詩班在幕後唱歌。
They are brewing a plot behind the scenes. 他們正在幕後策劃一個陰謀。
