Answer:
A
Explanation:
Heart cells are complex to find
Heart tissue is somewhat easy to find
Heart circulatory system is easy to find
The sailfish, able to swim up to 68mph.
I think all of them provide strong evidence, but the best would probably be the last one.
Hope this helps
B.
Humans are also part of ecosystems and if they cease to exist, human well being will be affected.
While doing exercise, one can control skeletal muscles only.
The body has three kinds of muscles, that is, skeletal muscle, cardiac muscle, and smooth muscle. The skeletal muscles are linked with the bones of the skeleton, that is why these are under control and are known as voluntary muscles.
On the other hand, the smooth muscles like skeletal muscle can never be under control. These muscles helps in pushing substances, like blood or food through organs. The cardiac muscle is also an involuntary muscle, which is found only in the heart. These muscles helps in contraction of the heart and can never be controlled.
