Question

please answer them it's to urgent for me please help me​

Answer 1

Answer:

18. 2

19. 4

20. 4

21. 2

Explanation:

hope it may help

Answer 2

Answer:

respectively 2,4,4,2

Explanation:

gastric juice is acidic because of the secretion of hcl

in mouth carbohydrate is digested by ptyalin

humans are the top level consumers

mode of nutrition is holozoic