Answer: is this an question
Explanation:
toxic substances can increase the risk for birth defect, miscarriages,etc.
Salt concentration is the factor among the following factors given in the question that does not vary between a fast flowing river and a pond that receives no water input. The correct option among all the options that are given in the question is the second option. I hope the answer comes to your help.
That would be temperature. (:
Hope this helps!
Answer:
beaver dams smooth out water flow by increasing the area wetted by the stream. This allows more water to seep into the ground where its flow is slowed. This water eventually finds its way back to the stream. Rivers with beaver dams in their head waters have lower high water and higher low water levels.
Explanation: Brainlest plz?