Do you have any idea it takes to successfully reach the top of Mount Everest?
A. whether
B. how
C. which
D. what
网友回答
A. whether
B. how
C. which
(答案→)D. what
解析：考查同位语从句的连接词。本题的同位语从句what it takes to successfully reach the top of Mount Everest作为名词idea的同位语。该从句中的take后面缺少宾语，故使用连接代词what。Whether属于连接词，在句中不充当任何成分。How属于连接副词，在句中做状语。Which指特定范围之内的某一个。故D正确。