--Look! He's running so fast!--H

--Look! He's running so fast!
--Hard to___________ his legs were~once broken.
A、know
B、imagine
C、realize
D、find
【正确答案】：B
【题目解析】：考查动词辨析。此句完整的形式为:It’S hard to imagine his legs were once broken句意为:“很难想象他的腿曾经摔断过。”know“认识，知道”;realize“意识到，实现”;find“发现，找到”;imagine“设想，想象”。故B项正确。