is our belief that improvements in health care will lead to a stronger, more prosperous economy.
A. As
B. That
C. This
D. It
网友回答
A. As
B. That
C. This
(答案→)D. It
解析：句意：那是我们的信念医疗保健的进步将促进一个更强大,更繁荣的经济。这里是that引导的是主语从句，它在从句中不作成分，it是形式主语，代替真正的that引导的主语从句。故选D。