Not until he left the house ______ to know how important the family was for him.
A、did he begin
B、had he begun
C、he began
D、he had begun
\n Not until he left the house ______ to know how importa - Unit 3 Argumentative Writing - 魔“方”作文——大学英文写作 - U校园 | 大学网课搜题引擎