Question

use letters to match each organ system to its primary function. (ms - ls1 - 3)
circulatory system
respiratory system
nervous system
digestive system
gas exchange (oxygen, carbon dioxide) between the body and the external environment
breaking down food and absorbing nutrients
receives and responds to input from inside and outside the body
transporting oxygen, nutrients, and waste

Explanation:

Circulatory - transport; Respiratory - gas exchange; Nervous - respond to input; Digestive - break down food.

Answer:

Circulatory system - Transporting oxygen, nutrients, and waste
Respiratory system - Gas exchange (oxygen, carbon dioxide) between the body and the external environment
Nervous system - Receives and responds to input from inside and outside the body
Digestive system - Breaking down food and absorbing nutrients