单选题 Uncle Sam ______very far when he remembered that he had not taken his notebook with him.

【正确答案】 C

【答案解析】解析：句意：当萨姆叔叔想起他没有带笔记本时，他还没有走出很远。“走”这个动作在remember之前一直延续，应该用过去完成时态，故选C。