Question

One of the most important questions they had to consider was _________ of public health.

A．what

B．this

C．which

D．that

Answer 1

D

试题分析：考查代词和从句辨析。如果把was后的部分看作表语从句，从句缺少谓语部分，因此不是表语从句，排除A、C；空白处指代的是“那个重要的问题”，即the question of public health，为避免重复，承前省略了the question，特指用that或the one，故选D。