Answer:
students at the university who speak three or more languages is 2082
Explanation:
given data
students = 31230
random sample = 255
speak three or more languages = 17
solution
we consider here numbers of students at university who speak three or more language = x
so here we will use proportions
= 
........................1
solve it we get
x = 2082
so here students at the university who speak three or more languages is 2082
<h2>
Answer: C) stars in these regions are hidden by interstellar dust grains.</h2>
Explanation:
Some areas of the Milky Way seem dark because those are areas of the galaxy that are hidden by huge columns of interstellar dust that we cannot see through the visible range of the electromagnetic spectrum (which is the range in which our eyes see).
However, to solve this problem, astronomers use telescopes that work in the range of infrared and radio waves, to observe a little more through this intersetelar dust.
GPS Satellite Constellation: The baseline satellite constellation consists of 24 satellites positioned in six earth-centered orbital planes withfour operation satellites and a spare satellite slot in each orbital plane. The system can support a constellation of up to thirty satellites in orbit.
The main reason why the tectonic plates move is the conversational currents. There is magma between the upper mantle and the asthenosphere that heats up at the upper mantle. The weight is so small that the magma rises with the help of these conversational currents. When the magma has ascended towards the asthenosphere, it has nowhere to go so the magma lies along the asthenosphere. There the magma cools down again because the asthenosphere is colder than the upper mantle, which makes the magma heavier and goes back down to the upper mantle, where the magma heats up again and everything starts all over again and so it goes on over and over again. Scientists have concluded that the earth's gravity causes two other processes that also cause the tectonic plates to move.
Ridge push - in the spreading zones, the sides of the tiles are raised and slide to the side as in a slide.
Slab pull - when a plate is pulled down by gravity in a subduction zone like an anchor.
