It suddenly occurred to him he had left his keys in the office. A．whether B．where C．which D．that
| D |
| 句意为: 他突然想起钥匙忘在办公室里。it 做形式主语，he had left his keys in the office 是后置的主语从句。成分完整，不含疑问语气。所以用that 连接。 【考点定位】sth occurs/occurred to sb 某人突然想起…… 事(物)做主语。如 An idea occurrs to me that the lights in the classroom have been on. |