Explanation:
it's water because one can live without eating food two days although the person may be weak but when it comes to water one can't live without water for even an hour the person will absolutely die
The conducting system of the heart consists of cardiac muscle cells and conducting fibers (not nervous tissue) that are specialized for initiating impulses and conducting them rapidly through the heart (see the image below). They initiate the normal cardiac cycle and coordinate the contractions of cardiac chambers. Both atria contract together, as do the ventricles, but atrial contraction occurs first.
The conducting system provides the heart its automatic rhythmic beat. For the heart to pump efficiently and the systemic and pulmonary circulations to operate in synchrony, the events in the cardiac cycle must be coordinated.
Answer:
4 - Any substance that contains germs that can be transferred to and from one person to another
"<u>THE FLU</u>"
According to the lesson the flu symptoms are more severe than the common cold. In addition to respiratory difficulties (sneezing, coughing, sore throat), the victim will also suffer from fatigue.
However Symptoms of the common cold may include runny nose, sneezing, congestion, coughing, sore throat, fever, and achy muscles.
The common cold doesn't have "fatigue" but the flu does.
