Which is the most common cause of cultural eutrophication

Select the star life cycle that is accurate

How do light years astronomers to determine the ages of distant objects in space ?

Ascientist observes certain changes in the physical features of a particular species over time. she concludes that the species has undergone evolutionary change. she wants to study the animals by analyzing their population. she’ll use . the population of this species is decreasing considerably. if this trend doesn’t change, this species will fall under the category of animals. this is a plato question,i need to make up his biology credit.