Railway interconnection between China and the B&R countries performed very well. In 2017, ______ saw the highest growth rate when railway serves as the transportation mode. （ ） A.export volume B.freight volume C.traffic volume D.import volume

Railway interconnection between China and the B&R countries performed very well. In 2017, ______ saw the highest growth rate when railway serves as the transportation mode. （ ） A.export volume B.freight volume C.traffic volume D.import volume

正确答案：A