---You could have walked here.---Yes. A taxi necessary.A. isB. wasC. isn’tD. wasn’t

问题补充：

---You could have walked here.

---Yes. A taxi necessary.

A. is

B. was

C. isn’t

D. wasn’t

答案：

A. is

B. was

C. isn’t

(答案→)D. wasn’t

解析：考查时态.根据上文,你应该不行来这儿.是的,出租车不是必须的.可知下文叙述的是过去该做的动作,故选D.