The main stems
of 38 rivers in the United States are at least 500 miles (800 km) long.
The main stem is "the primary downstream segment of a river, as
contrasted to its tributaries".[1] The United States Geological Survey (USGS) defines a main-stem segment by listing coordinates for its two end points, called the source and the mouth. Well-known rivers like the Atchafalaya,[2] Willamette,[3] and Susquehanna[4] are not included in this list because their main stems are shorter than 500 miles
Answer: C - GPS
GPS (global positioning system) uses the satellite to transmit and receive signal, indicating about one's location.
Hope it helped!
Answer:
Chan can use biodiversity as a tool by choosing different plants, animals and organisms for his research.
Explanation:
Biodiversity can be defined as the variety of life, which includes all plants, animals, humans, microorganisms, and much more. It includes all lifes and their interactions. Biodiversity is one of the most complex, as well as vital feature of our planet. A human depends a lot on biodiversity. The food we eat, the water we drink, the air we breath in, all depends on biodiversity. Like thatm it also contributes to a person's health. So Chan should study different organisms and their interaction with a huuman for his research.
Can’t have more than a certain amount
The city-states of ancient Mesopotamia were independent cities constructed around temples and entirely self-contained within mighty perimeter walls.<span> City-states were unified with each other only by their shared use of the Sumerian language. They spent most of their time engaged in conflict over resources.</span>
