across 指“从……的一边到另一边”，强调横过，多与动态动词连用。
along 指沿着一条直线在水平方向上运动。一般表动态，有时也与静态动词连用。
over 常和动态动词连用，指“从……上面越过”或“横越”；表静态时，指“在彼处”。
through 侧重从一端穿到另一端。
参考例句
1. I toured through Europe last summer. 去年夏天我周游了欧洲。
2. Can the table go through the door? 这张桌子能过得了那扇门吗？
3. They hewed a path through the jungle. 他们在丛林中开辟出一条路。
英英解释
adj.
1. having finished or arrived at completion
2. (of a route or journey etc.) continuing without requiring stops or changes adv.
1. from beginning to end
2. over the whole distance
3. to completion
4. in diameter
5. throughout the entire extent
