Hurricanes are severe cyclones with winds over seventy five miles an h

Hurricanes are severe cyclones with winds over seventy five miles an hour ______ originate over tropical ocean waters.

which

who

where

how to

答案及解析：本题考查定语从句A选项，句意：飓风是生成于热带海洋水域上空、风速达每小时75英里以上的强烈气旋。关系代词which引导的定语从句修饰名词winds.B，选项，从句的先行词是winds，who的先行词一般是人，故排除。C，选项，从句的先行词是winds，where的先行词一般是地点，故排除。D，选项，与题意不符，故排除。故正确答案为A选项。