Answer:
Over 800,000
<em>Arthropods are found in all parts of the world in a wide variety of environments, from the deep sea to the frozen arctic regions. Over 800,000 species of arthropods have been identified, but scientists estimate that there may be tens of millions of species in this phylum, many of them yet to be discovered!</em>
Explanation:
correct me if im wrong
<span>The Milankovitch theory explains the long term climate change and the </span>
Milankovitch cycles describe the effects of changes as a result of climate change. There are three Milankovitch cycles:about Earth's Eccentricity (the shape
of the Earth's orbit around the Sun), Axial tilt (the inclination of the Earth's axis in relation to its plane of orbit around
the Sun) and precession (the Earth's slow wobble as it spins on axis).
According to this, Milankovitch's cycles <span>are changes in earth's rotation and orbit around the sun that may trigger climate variation. (B).</span>
Answer: Most rocks do not contain organic material-most fossils are not organic anymore. One of the most common isotopes used in radiometric dating is uranium-235 or U-235. ... This makes it useful for dating rocks that are very old. Radioactive isotopes with short half-lives cannot be used for dating old rocks.
not 100% sure :/
<span>pretty sure its External pulmonary respiration because the blood gains o2 and loses co2 </span>
D. is the answer BTW this should be on chemistry topic not biology
