Not until he had fulfilled his mission did he realize that he was seriously ill.

Not until he had fulfilled his mission did he realize that he was seriously ill.

A、正确

B、错误

正确答案：A

答案解析：“Not until...”置于句首时，主句需部分倒装，即把助动词、be动词或情态动词提到主语之前。此句中，“Not until he had fulfilled his mission”放在句首，主句“he realize that he was seriously ill”部分倒装为“did he realize that he was seriously ill”，“had fulfilled”是过去完成时，表示“完成任务”这个动作发生在“意识到生病”之前，时态和语法结构均正确，所以该表述正确。