your answer is Nonpoint source pollution because this occurs due to a spreading of contaminants into a larger area and the actual source of the pollution can not be defined.
some examples are air, water and soil pollution. Mainly from vehicles the air is being polluted and we can not trace it.
same happens in case of water and soil many hospitals, factories, labs and even homes discard some pollutants and we can't find a single source.
if the source is only single place like a particular hospital or handicraft factory than we can call it as a point source pollution.
Q6: A
Q7:D
Q8:C
Reasoning
Q6: Based on all the other questions talking about common ancestors I deduced that to find a “common” ancestor they need to find things that are the same.
Q7: All arthropod have a exo skeleton for example a lobster or crab. They all have a head, abdomen and thorax for example ants. They all have legs with joints for example a spider.
Q7:So bones are traveled down by ancestors so the types of bones stay the same but natural selection has changed them to better fit their environment.
Answer:
By dating the rocks in Earth's ever-changing crust, as well as the rocks in Earth's neighbors, such as the moon and visiting meteorites, scientists have calculated that Earth is 4.54 billion years old, with an error range of 50 million years.
Yes thats one of its characteristics