设某商品的市场需求函数为Q=1-P/7，p为商品价格，则需求弹性函数为（）。

A (-1，+∞) B (-1，1] C (-1，1) D (1，+∞)

A (0，+∞) B (-∞，+∞) C [0，1] D (0，1]

A (0，1) B (1，2) C (0，2) D (2，3)

A 0 B 1 C 2 D 1/2

A -1 B 1 C 2 D -2

A 单调减少 B 单调增加 C 不增不减 D 有增有减

A F(x)-G(x)=0 B F(x)+G(x)=0 C F(x)-G(x)=C(常数) D F(x)+G(x)=C(常数)

A <img src="https://www.beizhujiaoyu.com/uploads/202208/16119739142961.png" width="166" height="41" /> B <img src="https://www.beizhujiaoyu.com/uploads/202208/161197391986631.png" width="164" height="41" /> C <img src="https://www.beizhujiaoyu.com/uploads/202208/161197392595831.png" width="182" height="34" /> D <img src="https://www.beizhujiaoyu.com/uploads/202208/16119739307781.png" width="190" height="34" />

A y=Clnx B y=Cln<img src="https://www.beizhujiaoyu.com/uploads/202208/161191194968391.png" width="20" height="52" /> C y=Cln(x+1) D <img src="https://www.beizhujiaoyu.com/uploads/202208/161191195634921.png" width="108" height="33" />