Answer:
C. At least five mass-extinction events have occurred during the last 500 million years.
Explanation:
- The history of mass extinct is related to the five mass extinctions that are caused over by the 350 million years n which many species have disappeared in there short geologic time.
- A massive extinction is caused in the Permian Triassic extinction event i.e about 250 mn years ago which on an estimate has killed 90% of the species.
- The Cretaceous–Paleogene extinction event that occurred over 66 million years ago is known to have wiped out the dinosaurs and many other species.
The border between the
transparent edge of the cornea and the white of the fibrous sclera is the limbus.
The limbus contains clusters of limbal stem cells that help to maintain the corneal
epithelium and to regulate corneal transparency and vision throughout life. The
limbus also acts as a boundary that protects the conjunctiva and its blood
vessels.
. Igneous rock is formed through the cooling and solidification of magma<span> or </span>lava<span>. The magma can be derived from </span>partial melts<span> of existing rocks in either a </span>planet<span>'s </span>mantle<span> or </span>crust<span>. Typically, the melting is caused by one or more of three processes: an increase in </span>temperature<span>, a decrease in </span>pressure<span>, or a change in composition. In this case, the "rock" is ice. The hot water has cooled through a change of temperature to create a solid structure (ice).</span>
It is system because bone nucleus and all the rest you put down are all a system structure in the body
