27 ! word bank: adaptation, biologist, control group, experimental group, hypothesis, law of conservation of energy, speciation, theory a(n) is an educated guess.

hypothesis, is a scientific way of guessing.

the most common type of reef is the fringing reef. this type of reef grows seaward directly from the shore. they form borders along the shoreline and surrounding islands.

blood enters the heart through two large veins, the inferior and superior vena cava, emptying oxygen-poor blood from the body into the right atrium of the heart. as the ventricle contracts, blood leaves the heart through the pulmonic valve, into the pulmonary artery and to the lungs where it is oxygenated.