. 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
网友回答
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。