How is the circulatory system involved with the respiratory system?
A. It moves air into the lungs.
B. It moves red blood cells to the larynx so sounds can be made.
C. Oxygen and carbon dioxide diffuse in and out of the capillaries that surround alveoli.
D. Blood pressure keeps the C-shaped rings in the trachea from collapsing.

A. It moves air into the lungs.

Explanation:  The respiratory system works directly with the circulatory system to provide oxygen to the body. Oxygen taken in from the respiratory system moves into blood vessels that then circulate oxygen-rich blood to tissues and cells.

question: which statement best describes the different properties of metals?

answer: they are shiny and bend without breaking.

since metals have certain characteristics properties, they include the following: they are ductile, malleable, shiny, hard, lustrous, flexible and they are good conductor of heat and electricity. so therefore, metals are not dull and they are not non-flexible as listed. instead, they are shiny and flexible.

hope this , have a good day. c;

answer: the correct option is d. enzyme

lactase and carbonic anhydrase are the examples of enzymes.

lactase is an enzyme, which is present in the small intestine of mammals. it in the digestion of the disaccharide, lactose ( milk sugar) by converting it into two monosachharide, which are glucose and galactose.

carbonic anhydrase is present in the red blood cells. this enzyme plays significant role in the transport of co₂. it in the conversion of co₂ and h₂o into carbonic acid, which is then dissociated into bicarbonate ions and hydrogen ions.