Hi Ace22704,
Answer - natural observation
I think this experimental method is a better option because its in a natural environment where the kids dont know whats happening unlike the suveys where you ask them questions which is probably a bad idea because they might feel scared and just change their minds.
I think computers. hope that helps.
Answer:
The circulatory and respiratory systems work together to circulate blood and oxygen throughout the body. Air moves in and out of the lungs through the trachea, bronchi, and bronchioles. Blood moves in and out of the lungs through the pulmonary arteries and veins that connect to the heart.
Explanation:
Hope this helps!
Good Luck!