. I to the top of the tree but I fell off it and hurt my leg.A. must have climbedB. was

问题补充：

. I to the top of the tree, but I fell off it and hurt my leg.

A. must have climbed

B. was able to climb

C. could have climbed

D. should have climbed

答案：

A. must have climbed

B. was able to climb

(答案→)C. could have climbed

D. should have climbed

解析：本题考查情态动词。句中could have done表示“本可以做”。句意：我本可以爬到树顶，但我掉下来了腿受伤了。