Answer:
I think its that the circulatory system keeps blood flowing and supplies blood to the organs and keeps the heart pumping and the respiratory system keeps you breathing an supplies oxygen to the organs
Explanation:
Answer:
research question: how do different humidity levels affect the heights of different types of trees
independent variable: humidity level
dependent variable: tree height
constants: temperature, light, duration of time
control group: tree left outside in normal conditions
Explanation:
Answer:
A Y-chromosome
Explanation:
Males have one X and one Y chromosome
Answer:
An underground cavern collapsed
Explanation:
I did research