问题补充：
entered the office when he realized that he had forgotten his report.
A. He hardly had
B. Had he hardly
C. Hardly had he
D. Hardly he had
答案：
A. He hardly had
B. Had he hardly
(答案→)C. Hardly had he
D. Hardly he had
解析： hardly在句首，主句要倒装，故可以排除其他三项。
