If , these injuries can develop into more serious problems.
A. left untreating
B. left untreated
C. leaving untreated
D. are left untreated
网友回答
A. left untreating
(答案→)B. left untreated
C. leaving untreated
D. are left untreated
解析：考查省略句，当主从句的主语一致的时候，可以省略从句的主语和be动词，这句话省略的就是后面的主语these injuries和are，完整的说是If these injuries are left untreated, these injuries can develop into more serious problems.这里的leave...+adj/adv/prep 表示使。。。处于某种状态。译为：如果被这些伤口不处理可能会发展成更严重的问题。