问题
选择题
The question that puzzled them is ____ they can get rid of the air pollution in the area.
A．how is it that
B．that is how
C．what is that
D．how it is that
答案
答案：D
题目分析：考查强调句的特殊问句做表语从句：句意：那个令他们无法理解的问题是-怎么才能-他们才可以除掉这里的空气污染。强调句的特殊问句是：特殊疑问词+is it+that…，这里做表语从句，用陈述语序，所以选D。