Pratt failed many times but he finally to find a successful way to solve the problem.
A. broke out
B. broke up
C. broke down
D. broke through
网友回答
A. broke out
B. broke up
C. broke down
(答案→)D. broke through
解析：考查动词短语辨析。A（战争，火灾）爆发；B关系破裂，分解；C机器出故障；身体垮掉；分解；D突破；句意：Pratt多次失败，但是他终于取得了突破，成功地找出了解决问题的方法。根据句意说明D正确。