Answer:
C. H and O
Explanation:
Almost 99% of the human body's mass is made up of six elements: oxygen, carbon, hydrogen, nitrogen, calcium and phosphorus, in that order.
Element Symbol % in body
Oxygen O 65.0
Coal C 18.5
The human body is composed of 60% water, that is, H2O.
Natural regeneration of forests and woodlands is the process by which new trees grow from seeds that have fallen and germinate where they have fallen. The biggest problem with natural regeneration is that is unpredictable. As a result, it cannot be used for commercial farming. For most of the last two or three hundred years, forests and woodlands have restocked by using transplants grown in nurseries. The young trees are planted in equidistant rows. This allows each tree the best possible change of optimal growth.
Twenty two thousand so the answer is c
The stage that scientists begin to ask questions and attempt to explain observations is A. forming hypotheses. This is because a hypothesis is basically a testable question about observations scientists make.