Give 4 ways gills are adapted for gaseous exchange?

1)Each gill consistss of plates called gill filiament, each filliament covered in tiny structures called lamelle meaning the have very large surface area. 2)Lots of blood capiliaries speeding up diffusion. 3)Thin surface layer minnimising distance gases have to diffuse. 4)Blood and water travekin different directions maintaining high concentration gradient so as much oxygen diffuses as possible.