Question

When the students heard the alarm, they all hurried to        they thought was an emergency exit door．

A．what

B．which

C．where

D．who

Answer 1

A

试题分析：此处to是介词，其后是介词的宾语从句，what在宾语从句作主语。句意：当学生们听到警报声，他们都急忙冲向他们认为的应急出口。