问题
选择题
. Will you please keep quiet now? You shouldn’t talk until ________ to.
A．asking
B．having asked
C．to ask
D．asked
答案
答案：D
考查状语从句的省略。句意：请你现在保持安静好吗，你不应该说话直到你要求被说。完整形式为：You shouldn’t talk until you are asked to.故选D。