Answer:
The USA became involved in Vietnam because it feared the spread of communism. The USA were unable to defeat the Vietcong and were met with growing opposition to the war back home.
this is the only one I can answer, I'm sorry. I hope this helps though
Plants, algae, and a group of bacteria called cyanobacteria are the only organisms capable of performing photosynthesis
Increased heating, increased evaporation
Found at the lowest point of a large drainage area, these seasonal, marsh-like ponds collect and store water from rain and runoff. Unlike vernal pools, playas generally fill when temperatures are unsuitable for plant growth, and often the water is salty, alkali or both.
source- google
