Answer:
because harmful substances often chemicals or microorganisms contaminate a stream, river, lake, ocean, aquifer, or other body of water, degrading water quality and rendering it toxic to humans or the environment.
Explanation:
Hope This Helps!!!
Answer:
A, D Is your answer
Explanation
Researching bones, animals, and DNA can tell you a lot about the
colonial history of a region. Even clothing, vehicle parts, and
plant life can tell how people lived in colonial times.
An astronaut is able to float slightly on the moon due to the gravity, the gravity being 1.62 m/s² which would be lighter then the earth's which is 9.78 m/s².
B. Allele is a form of gene.
Answer:
An analysis of 5,000-year-old genetic material from preserved human remains found in Sweden suggests that people moving from southern to northern Europe spread agriculture across that continent long ago.
In addition to agricultural know-how, the intrepid farmers brought their genes: They interbred with hunter-gatherer communities to create modern humans living in Europe today.
"Genetic variation of today's Europeans was strongly affected by immigrant Stone Age farmers, though a number of hunter-gatherer genes remain," study researcher Anders Götherström, of Uppsala University in Sweden, said in a statement.
The results of this study, to be published in the April 27 issue of the journal Science, match up well with previous archeological evidence of farming in Europe.
Explanation:
hope it help to you
