Then the K resemble theory was used to translate the surface crack to middle through crack.

并利用K相似原理，把表面裂纹问题转换为中心贯穿裂纹问题；

youdao

My neighbour spies on me through a crack in the fence.

我的邻居通过篱笆墙的缝隙窥探我。

《柯林斯英汉双解大词典》

Kathryn had seen him through a crack in the curtains.

凯瑟琳曾从帘子的裂缝看到过他。

《柯林斯英汉双解大词典》

So if air can get through a crack as a draught, the ball should be able to squeeze through, and then rearrange itself on the other side.

BBC: New lead for fireball riddle

Minutes later, the officer saw Craig gazing into his stall through the crack between the stall door and the frame, fidgeted with his fingers and returned to gazing through the stall for about another two minutes, the documents state.

NPR: Sen. Craig Says He Did Nothing Inappropriate

She knew that if she did her life would split open and she would slip through the crack.

NEWYORKER: Temporary