Answer:
Cardiac muscle tissue
Explanation:
Myocardium or heart muscle is a special type of muscle (differ than striated and smooth) and it is the main tissue of the walls of the heart.
Heart muscle consists of individual heart muscle cells (cardiomyocytes) which are joined together by intercalated discs. It also contains collagen fibres and other substances that form the extracellular matrix.
Heart muscle has a "special" mode of contraction: action potential triggers the release of calcium ions from the cell's internal store, the sarcoplasmic reticulum.
B. One
because an independent variable is something you change. So in a scientific experiment you only change one thing. If you happen to change more than one thing then the test becomes unfair therefore you should repeat and make sure that only one thing is changed this time.
Saline solutions have the same or close to the same amount of salt as our blood does, so we get the amount of salt needed for our bodies. During blood loss, you lose the salt you need, so they're basically adding it back in with the saline solution, making your electrolyte balance go back to normal level. It also gives us the right amount of water to keep us hydrated.