— What did he think of the trip to Beijing last month？
— He had such a good time he visited the Great Wall.
A. until
B. that
C. where
D. when
网友回答
A. until
B. that
C. where
(答案→)D. when
解析：考查连词：A. until直到，B. that那C. where哪里，D. when 当….时候，句意：--你认为上个月在北京的旅行怎么样？--参观长城的时候他玩得非常的高兴。选D。