Need the heart is a muscular organ that pumps blood. blood that contains waste materials is brought to the heart by blood vessels. this blood enters the (left atrium, right atrium, right and then moves down. the presence of the (atrioventricular valve, valves in the aorta, valves in the prevents the backflow of blood inside the heart

Over time the trees in african have increased in length. many species have had to adapt to this change in order to survive. which of the following is a structural adaptation that has the african giraffe meet this change? question options: the african giraffe has become a faster at running from its predators. the african giraffe's neck has increased in size over the years. the african giraffe have moved to another part of africa. the african giraffe has not adapted and struggles to survive.

As soon as possible this assignment is due in 5 minutes atoms in a molecule are bonded together by sharing, gaining, or a. photons b. protons c. neutrons d. energy f. electrons

Environmental differences within ecosystems are generally caused by