Much of the criticism has focused on the

问题选择题

Much of the criticism has focused on the railway’s online purchasing system，which has been

unable to _________ the huge demand．

A．take notice of

B．attach importance to

C．show preference for

D．keep pace with

答案

题目分析：A．take notice of注意，B．attach importance to重视， C．show preference for偏爱， D．keep pace with跟上…的步伐，句意：很多批评是针对铁路的网上购买系统，这已经不能赶上巨大的需求。选D。