Over the past l00 years sea levelsteadily as a result of global warmingA. had increasedB.

问题补充：

Over the past l00 years，sea levelsteadily as a result of global warming．

A. had increased

B. has been increasing

C. increased

D. is increasing

答案：

A. had increased

(答案→)B. has been increasing

C. increased

D. is increasing

解析：考查时态，句意：在过去的100年中，作为地球变暖的结果海平面一直在稳定的上升。可知本句描述的是现在已完成的一直在进行的动作，故用完成进行时态。选B。