Letter on position 1 (b) changed: 7 words curs furs gurs lurs nurs ours purs Letter on position 2 (u) changed: 2 words bars bors Letter on position 3 (r) changed: 8 words bubs buds bugs bums buns buss buts buys Letter on position 4 (s) changed: 10 words bura burb burd burg burk burl burn burp burr bury