Why do astronomers think that there may be other advanced civilizations? What technologies are astronomers using to look for life on other planets? Why?

What are the challenges of looking for Dyson spheres?

Astronomers have theorized that there could be three types of civilizations. What are they? How would they be recognized? Which one has been ruled out so far?

Do you think an advanced civilization may exist in the universe? Why or why not?

PLZ help :)

oak trees? ? what was listed

a- multicellular

b-eukaryotic

c-no cell wall

d-heterotrophic

e-autotrophic

1: most common garden plants prefer loam — soils with a balance of different-sized mineral particles (approximately 40% sand, 40% silt, and 20% clay) with ample organic matter and pore space. however, some plants grow better in sandy soils, while others are well-adapted to clay soils.

2: available water capacity is the maximum amount of plant available water a soil can provide. it is an indicator of a soil's ability to retain water and make it sufficiently available for plant use. available water capacity is the water held in soil between its field capacity and permanent wilting point.

3: it is the same for all living things (plants and animals). it also includes very tiny organisms that our eyes cannot see. they are known as microorganisms, and include viruses, bacteria and fungi.

the actual answer was 160934