（2006年普通高等学校招生全国统一考试浙江卷，4） 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
D. It
解析：本题考查it作形式主语，代替that improvements in health care will lead to a stronger, more prosperous economy，而其他选项均不可以充当形式主语。