7. In order to obtain more information about the relationship between phosphates, nitrates, and plant growth, which of the following procedures should be performed next?
Your Answer is
Correct Answer is B
Explanation
The stem of the question asks to study the relationship between plant growth and P phosphorus and N nitrogen, so when designing experiments, there should be dependent variables (the growth of a certain plant) and independent variables (different concentrations of phosphorus and nitrogen growth environment), so it is B, algae algae are plants