4 is correct. In a wide expanse of space, gravity drew dust and gas together to create the solar system. The sun formed first from the vast material.
Answer: Option B.
Explanation:
The first experiment of the passage shows that treatment with TGFBR1 and TGFBR2 antagonists led to lower levels of epithelial cell production. For this conclusion to be strongly valid, we want to show a positive correlation between TGFBR activity and epithelial proliferation.
The tricuspid valve, located between the right atrium and the right ventricle; the pulmonary (pulmonic) valve, between the right ventricle and the pulmonary artery; the mitral valve, between the left atrium and left ventricle; and. the aortic valve, between the left ventricle and the aorta.
