求翻译：最著名的是一线天，只见悬岩断壁上一隙通明，全长120米，高40米，宽仅盈尺，最窄处只可侧身而过。 徐霞客在游记中称“缝隙一线，上劈山巅，远秀山北，中不能容肩。余所见一线天数处，武夷、黄山、浮盖，曾未见若此大而逼、远而整者”。是什么意思？

The most famous is the thin strip of sky, saw cliff broken walls, brightly lit, a gap length of 120 meters, 40 meters high, Kuan Jin Ying Chi, the narrowest point is only sideways. Xu said in Travels in the "seam line, split mountains far Xiushan North, can not be accepted in the shoulder. I can see