In 1913,Titanic was the largest and most luxurious cruise ship that---
问题描述：
In 1913,Titanic was the largest and most luxurious cruise ship that---
A.was ever built
B.has ever been built
C.has ever built
D.had ever been built
答
In 1913,Titanic was the largest and most luxurious cruise ship that---A.was ever builtB.has ever been builtC.has ever builtD.had ever been built选项中有ever,所以只能用完成时因为前面主句是用was一般过去...