A. whenever the crusts move over mantle B. when the plates move towards each other C. in the narrow boundaries where two plates meet D. to be the major topographical feature of the Earth 参考答案:C 答案解析:[定位] 第1段最后一句。 [解析] 选项C是对该句的同义改写。 [点睛] ①文章中没有提到选项A中the crusts move over mantle这种现象;选项B提到的现象在第2段