Occurs when ecosystems change over time through the progressive replacement of species.

One statements is an example of a scientific observation. another statement is an example of a scientific explanation. identify the correct statement for each category to illustrate how scientific explanations are inferred from scientific observations.

Aperson with age is more likely to catch diseases that healthy people usually don’t catch.what are these infections called?

Which of the following is not a possible effectof increasimg carbon dioxide levels in the atmosphere ?