at (1)表示在小地方; (2)表示“在……附近，旁邊”
in (1)表示 在大地方; (2)表示“在…范圍之內”。
on 表示毗鄰，接壤
to 表示在……范圍外，不強調是否接壤
He arrived at the station at ten.
He is sitting at the desk.
He arrived in Shanghai yesterday.
Jiangsu lies in the east of China.
Russia live on the north of China.
Fujian is to the south of Jiangsu Province.

at (1)表示在小地方; (2)表示“在……附近，旁邊”
in (1)表示 在大地方; (2)表示“在…范圍之內”。
on 表示毗鄰，接壤
to 表示在……范圍外，不強調是否接壤
He arrived at the station at ten.
He is sitting at the desk.
He arrived in Shanghai yesterday.
Jiangsu lies in the east of China.
Russia live on the north of China.
Fujian is to the south of Jiangsu Province.