Ok here we go:
Science starts with observing which leads to hypothesis, which is tested by experiments.
The other two i am not sure of. Hope i was a help to you. One thing you can do to figure out the other two is google: "what type of science includes medicine and envirnmental science", and do the same for the other one.
Answer: the relative differences in arrival times of the S and P seismic waves at several recording stations tell scientists about the different speeds those waves were traveling at, which in turn gives information about the density of the material the layer is made of, and how thick the layer is in several directions.
Explanation:Earth's layers
The most basic reason that cells are stained is to enhance visualization of the cell or certain cellular components under a microscope. Cells may also be stained to highlight metabolic processes or to differentiate between live and dead cells in a sample.
Answer:
A
Explanation:
The pulmonary artery carries de-oxygenated blood from the right ventricle of the heart to the lungs. It is the only artery that carries de-oxygenated blood. This blood is usually from the tissues and has a lot of carbon dioxide from the cellular respiration of cells around the body. The blood is pumped to the lungs to be oxygenated and the carbon dioxide expelled.
Oxygen was initially created in Earth's atmosphere by algaes. It is estimated that marine plants produce between 70 and 80 percent of the oxygen in the atmosphere. Nearly all marine plants are single celled, photosynthetic algae. Hope this answers the question.
