Rainwater picks up carbon dioxide from the air and as it percolates through the soil, which turns into a weak acid. This slowly dissolves out the limestone along the joints, bedding planes and fractures, some of which become enlarged enough to form caves.
A) single loop
Fish have a two-chambered heart in which a single-loop circulatory pattern takes blood from the heart to the gills and then to the body.
B) left ventricle → left atrium → pulmonary artery
<span>Oxygen-rich blood is carried to the brain via the blood vessels. BLood vessels are the living life support of the body because it carries blood from the heart to the other organs of the body. Everyday the heart pumps almost 14,000 liters of blood to provide the needs of the body and at the same time, the blood vessels also carries waste from the body and out.</span>
Genes are found in every cells nucleus and are made of strands of dna
