I argued that if I spent less time exhausting myself at exercises in the morning, I would keep my mind fresh for reading when I got home from work.(我辩解说,早晨少耗费精力锻炼,晚上下班回家看书时头脑更清醒些。)——《新概念英语》扩展问题:表达“在某事件上...”的意识时,“at/on/in +事件”各有何不同?可以互换吗?