I am thinking the rock that forms from lava that cools quickly is D) Obsidian.
They both help to keep all of the gas and dust in place and not just float off. it evolved from a solar nebula. stars were created in the solar nebula and they would attract gas and dust and became bigger and bigger.
Cell membranes serve as barriers and gatekeepers. They are semi-permeable, which means that some molecules can diffuse across the lipid bilayer but others cannot. Small hydrophobic molecules and gases like oxygen and carbon dioxide cross membranes rapidly.
The presence of two deltas indicates a 'plain whorl', a common thing that 24% of people have in common.
Answer:
Traditionally, these fauna have come to represent an important development in the evolution of life on Earth, because they immediately predate the explosion of life-forms at the beginning of the Cambrian Period 541 million years ago.
Explanation:
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