Firms that use computers have found that the number of staff
Firms that use computers have found that the number of staff ______ is needed for quality control can be substantially reduced. [A] whose [B] as [C] what [D] that 选哪个?为什么?请翻译整句
选C. What 在此处有双重意义=the thing that 既做主语又做引导词。 Firms that use computers have found that the number of staff what is needed for quality control can be substantially reduced. 运用电脑的公司发现,从事质检方面的员工的数量实质上可以裁减。