Question

fill up the blanks a.The cells of the cork are heavily thickened _with that makes them impervious to gases and water. b._is the main biological process that returns oxygen to the atmosphere.

Answer 1

Answer:

here's your answer mate

Explanation:

a. suberin

The walls of cork cells are heavily thickened with an organic substance, suberin, Suberin makes these cells impervious to water and gases.

b. photosynthesis

Oxygen is returned to the atmosphere through photosynthesis.

hope it helps u