The young lady was careful . A. not repeating her mistakeB. not repeated her mistakeC. to

问题补充：

The young lady was careful .

A. not repeating her mistake

B. not repeated her mistake

C. to not repeat her mistake

D. never to repeat her mistake

答案：

A. not repeating her mistake

B. not repeated her mistake

C. to not repeat her mistake

(答案→)D. never to repeat her mistake

解析：这是短语be careful not to do sth.的搭配，故选D。