The introduction of containers in transport greatly _______ carr

The introduction of containers in transport greatly _______ carriage of goods.
A、economizes
B、speeds
C、facilitates
D、facilitate
【正确答案】：C
【题目解析】：A:节约  B:速度  C:促进  D:促进  
本题缺少谓语动词，主语是The introduction of containers，因此本题用第三人称单数。句意：集装箱在运输中的引入大大方便了货物的运输。