Switch A and D, but other than that your answers are correct.
An astronomical body is an object in space.
A comet is a celestial object consisting of a nucleus of ice and a stream of gas and dust.
A moon is an astronomical body that orbits around a planet.
A galaxy is a system of start held by gravitational attraction.
It is true that r-related species have a short life span and an early reproduction cycle. R-related species also known as r-strategist have a short and simple life span. Due to their simple life span, their nutrient exchange rate with the environment is rapid. Unlike K-selected species, they have the ability to reproduce at a young age. They reproduce a large number of off-springs, but many of their off-springs tend to die before attainment of their reproductive age.
I think it is used to produce energy mainly hydroelectricity which is electricity from water
Organism like frog and toads. Maybe even all Amphibians.
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