答案：B

当hundred,thousand这些词与具体数字连用时，习惯上用单数，而且也不后接介词of。如：He was prepared to pay two million. 他愿意支付200万。当这些词不与具体数字连用，而是表示不确定的泛指数时，则不仅要要用复数，而且要后接介词of，然后才能接名词。如：The sun was shining. Thousands of people were lying on the beach. 阳光灿烂，数以千计的人躺在海滩上。