问题
选择题
All over the world the mobile phone has leaped from being an impossible luxury in the early 1980s to most people would now call a necessity.
A．which
B．that
C．what
D．when
答案
答案：C
考查名词性从句。句中what引导宾语从句，在从句中作宾语，call及双宾语，故选C。