问题
选择题
Much to the couple’s comfort, their income is now double ______ it was five years ago.
A．that
B．than
C．which
D．what
答案
答案：D
考查宾语从句。is now double是谓语部分，所以后面跟的是宾语从句，宾从______ it was five years ago缺少was的表语，所以用what引导。选D。