You shouldn’t talk until to.A. askingB. having askedC. to askD. asked

问题补充：

You shouldn’t talk until to.

A. asking

B. having asked

C. to ask

D. asked

答案：

A. asking

B. having asked

C. to ask

(答案→)D. asked

解析：句意：你不应该讲话直到你被问。这里until后是省略句，完整的是until you are asked；省略的条件是从句的主语与主句的主语一致，并且从句的谓语动词用be动词，这里把从句中的主语与be动词都省略，故选D。