1) they have similar chemical properties.
for example fluorine from the 17th column is a non metal so does all the elements of that group.
2)they have same valence electrons in their outermost shell
example
electronic configuration of
hydrogen 1, lithium 2,1, sodium 2,8,1 and so on.
3) have same valency.
Well living is having life while biotic is pertaining, or produced by life or living organisms. :)
Question 1: The correct answer should be the one that shows the producer first, (->) followed by the herbivore, (->) with the carnivore last.
Producers are organisms that harvest their own 'food' using things like the sunlight and water. Examples of producers are grass and other vegetation.

The herbivore, or an organism that consumes only vegetation and/or algae, consumes the producer.

⇒

The carnivore consumes meat, or other animals such as the herbivore. It's the last.

⇒

⇒

Therefore the answer is
B.
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Question 2: I'm pretty sure that succession as well as regrowth after volcanic eruption (Just look at Mount St. Helens. After 30-35 years after the eruption, nature is
still recovering) happens over time/slowly. I would say global warming [C](?) would be the answer.
Temperate grasslands are composed of a rich mix of grasses and forbs and underlain by some of the world’s most fertile soils. Since the development of the steel plow most have been converted to agricultural lands.