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:
C. a toy train is the item that has characteristics similar to a scientific model.
Animal cells communicate via their extracellular matrices and are connected to each other via tight junctions, desmosomes, and gap junctions
