0The prepositions are both fine and natural, but in AmE we'd add a third, so to speak. We use the expression (idiom) "line up" to form a line. I guess BrE is "que." I don't know if it can stand alone, or if it's "que up," or if I'm spelling it correctly.02br 02br 00I wonder if "up'" becomes an adverb in "line up."0-
0Search:02br 05002br 02br 00for 02br 01b00"lined along the walls"02b02br 01b00"lined against the walls"02b02br 00and you'll see that both work. 02br 00However, "against" means close or even in contact with the walls, which the other doesn't. 02br 02br 00<> 02