D. high and low levels of silica in the different type of lava.
Explanation:
The volcanoes have different types of explosions. Some tend to be highly explosive, some less explosive, some don't have explosions at all, while some have combinations of different eruptions. The reason for this diversity in the eruption types is mostly the composition of the magma, or rather how high is the silica content in it.
Basically, the higher the silica level in the magma the higher the explosiveness, and the lower the silica level the lower the chances of explosiveness. This is the case because the higher amount of silica makes the magma thicker, so the gasses are trapped and they explode, while when the lower silica content makes the magma less thick, so the gasses are not trapped and explosions are lacking.
<u>Answer:</u>
<em>Rigel and Betelgeuse </em>
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<u>Explanation:</u>
Rigel and Betelgeuse are counted in the brightest stars of the galaxy.
They form a pair in the Orion constellation.
The Rigel star is situated near the Equator. This star is invisible in the region around and above of latitude 82°N and can be seen from any part of the world. It is a blue white giant star. This makes Rigel helpful in navigation.
Betelgeuse is a red giant star which is visible from naked eye. It has the same diameter as that of Jupiter.
