【题目】Oil, exported from Iran to Europe, ______ by tankers. ( )
A.used to be transported/have been built up
B.used to being transported/have built up
C.was used to be transported/had been built up
D.was used to being transported/will be built up
【答案】A
【解析】
句意：从伊朗出口到欧洲的石油，过去由油轮运输/建造。根据句意可知此句用过去时的被动语态，或者现在完成时的被动语态。故选A。
