Once by the expert, the girl will improve her English in a few months.
A. being taught
B. to be taught
C. taught
D. teaching
网友回答
A. being taught
B. to be taught
(答案→)C. taught
D. teaching
解析：本题考查状语从句的省略。该部分补充完整是：Once he was taught。连词when, while, if, as, though / although, until, once, whether, unless, where等引导的状语从句中，当主句的主语和从句的主语一致时，常省略跟主句相同的主语和be，只剩下主要的部分。