Kangaroos are mammals that lack a placenta. therefore, they must have an alternate way of supplying the developing embryo with

a. carbon dioxide
b. enzymes
c. nutrients

Which system revise and send electrical signals throughout the body

The pharynx is the structure in the body that serves as a pathway of both air and food. how does the body make sure that food does not get into the lungs? the salivary glands secrete enzymes that pull food out of the air pathway. the small intestine pushes the air out of the digestive system. the pancreas breaks down food in the air pathway. the epiglottis closes the air pathway so that food will not enter it.

With the word calcite wich completes the analogy mineral, erosion, marble, or aragonite