I was leaving the office when it suddenly to me that I had forgotten my keys.
A. struck
B. happened
C. occurred
D. hit
网友回答
A. struck
B. happened
(答案→)C. occurred
D. hit
解析：考查固定句式。固定句式：sth occur to sb某人突然想起某事；本句中的it是形式主语，主旨的主语是后面的主语从句that I had forgotten my keys.句意：我正要离开办公室，在这时我突然想起我忘记带钥匙了。故C正确。