They produce saliva which is essential for the breaking down of carbohydrates.
The correct answer is: desertification.
Desertification is a process in which a land which was not a desert before, becomes one. This process can include drying out- through for example loss of water source, such as river diversion- and the loss of vegetation.
There is no image or choices so what exactly do you want us to answer.
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.
