<h2>540 million years ago
</h2>
Paleozoic.
Era immediately follows Precambrian It lasted about 4.5 billion years.
When did abundant fossil evidence first appear in the geologic record.
540 million years ago.
Part 1;
Because there is only limited amounts of fresh water on the Earth the rest is salt water; which humans can not survive on as the salt dehydrates our bodies instead of hydrates.
1) The more we try to get the the fresh water the more we will likely make more pollution.
2) The more we use the less there is.
3) Everything needs water.
Part 2; no idea I believe it is the ice caps, as it is fresh water in the ice caps and not a lot of humans up there to pollute the runoff.
The answer is A
This is because 90% of energy is lost when we go up one trophic level. This means that even the the consumers tend to be larger in size, they are fewer in number and need to eat more in order to sustain themselves.
ANSWER: MITRAL VALVE STENOSIS
EXPLANATION:
The child have the risk of having MITRAL VALVE STENOSIS. It is also referred to as mitral stenosis.
Mitral valve stenosis occurs as results of the mitral valve opening narrowing. Which effect to less blood flowing through it.
The mitral valve is located between two chambers (the atrium and the ventricle) on the left side of your heart.
However, Mitral valve stenosis can lead to different health issues, including blood clots, difficulty breathing, fatigue, and heart failure.
Mitral valve stenosis is specifically caused by rheumatic fever (a childhood disease). This rheumatic fever occurs has a result of the body's immune response to an infection associated with the streptococcal bacteria.
Acute rheumatic fever affects the joints and the heart greatly. It causes joints inflammation temporarily and in severe case causes chronic disability.
Nevertheless, this cardiac complication have treatment and it is based on whether the affected individuals shows symptoms. Medications like blood thinners or anticoagulants (to reduce the risk of blood clots), diuretics, antiarrhythmics (to cure abnormal heart rhythms), beta-blockers (to slow your heart) etc, are being administered based on the level of the complication.
Answer:
The American bison is the national animal of USA..