They loosen up to be tighten again
Answer: D
Explanation:
A change in the amount of polar ice will alter how ocean currents move
The heart’s electrical system is responsible for making and conducting signals that trigger the heart to beat. These signals cause the heart’s muscle to contract. With each contraction, blood is pumped throughout the body. This happens 24/7 without us having to monitor it all the time so that our heart does not stop.
It shows that a scientist can be creative because they used the fish's coughing technique to search for contaminated water.
