I think walking is an easy way to keep fit. ______ but Jim doesn't think so. [ ]

A.I disagree

B.I agree

C.I'm afraid not

D.I'm not sure

进行建设项目敏感性分析时，可以通过计算（）确定敏感因素。

A.盈亏平衡点

B.评价指标变动率

C.不确定性因素变动率

D.变动因素临界点

E.敏感度系数