are areas around the world that support similar communities of species, and are smaller, local communities within these areas.

Jolliet and la delle

Either b or c . i did this before

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.