- Suppose you collect 1000 kilograms of sea salt by evaporating ocean water. How much of the 1000 kilograms is sulfate? - if you wanted to collect 245 grams of sea salt, how many kilograms of ocean water would you need?

Its led to migrationits led to death 

It's between the sagittarius and perseus arms of the milky way.

The circumcenter is  equidistant  from each vertex of the triangle. the circumcenter is at the  intersection  of the  perpendicular bisectors  of the triangle's sides. the circumcenter of a right triangle falls on the side opposite the right  angle. the incenter  of a triangle is always inside it.

1. why do astronomers think that there may be other advanced civilizations?
because  it was discovered that there are other planets like earth out there, able to  accommodate life forms.
2. what technologies are astronomers using to look for life on other planets? why?  
they  have used radio telescopes, but now they use laser telescopes   to track laser communications.