Scientists utilize models for a variety of different purposes, but each type of scientific model has limitations. what might be a
limitation of existing solar system models?
a. they are not based on experimentation
b. they are used for prediction
c. they cannot be changed.
d. they are based on current knowledge
select the best answer
pls !

Which of the following best describes the purpose of the parathyroid hormone? a. it decreases the blood calcium level and decreases blood phosphorus level. b. it decreases the blood calcium level and increases the blood phosphorus level. c. it increases the blood calcium level and increases blood phosphorus level. d. it increases the blood calcium level and decreases blood phosphorus level.