升级换代 updating and upgrading (of products) 生计疑难题目 bread-and-butter issue 生命bank bank for holding the donated organs and remains of dead persons for medical use ..
The firstprolonged and impassionedcontroversy in theCongressinvolving apurefoodissue took place in 1886, pitting the reigning champion, butter, against a challenger, oleomargarine.