the government recovers the vehicle purchase tax and the oil prices go up continuously, the sales of the vehicle in China are still increasing every year.
A. When
B. Once
C. Since
D. While
网友回答
A. When
B. Once
C. Since
(答案→)D. While
解析：句意，虽然政府恢复了机动车的购买税，以及油价持续上涨，汽车在中国的销量仍然每年上涨。When当……时候Once一旦Since自从While虽然，根据题意，故选D。