Which of the following is not a function of lymphatic system?

Associated with the thymosin production: 

Sucrase helps the digestion of __________. 

Lipase  helps the digestion of __________. 

Interconversion of amino acid is a function of ______.

The GI tract is about _______ meters long.

The outermost layer in the wall of the GI tract.

Amylase helps in the digestion of __________. 

Phagocytic cells in lung alveoli: 

Lipid metabolism is a function of __________.