Not until Mr. Lee came in ______we stop talking.

Not until Mr. Lee came in ______we stop talking.
A、did
B、do
C、does
D、done
【正确答案】：A
【题目解析】：当Not until位于句首时，主句要用倒装。其结构为Not until +从句+助动词+主句主语+谓语+…。