Plants cell walls are made of 
fiber keratin alveoli cations matter CO 2 porous Cane.
A B C D E F G H
Basically, fiber is cellulose .
Plants cell walls are made of fiber.
Plants cell walls are made of  (A) fiber (B) keratin (C) alveoli (D) cations (E) matter (F) CO 2 (G) porous (H) Cane.