Which of the following describes the relationship between elements of an ecosystem? A.) Elements of ecosystems are mutually dependent on each other.
B.) Abiotic elements are dependent on each other, while biotic elements are not dependent on each other.
C.) A cause and effect relationship is limited to abiotic elements only.

The first immigrants to settle in what is now the united states were the ancient ancestors of modern native americans. the precise routes of those first north american immigrants are disputed, but there is no uncertainty about the fact that every human being on the continent is either a recent immigrant or a descendant of earlier immigrants. since the first immigrants came here from asia more than thirteen thousand years ago, there have been four large and easily recognizable modern waves of immigrants into the united states.

The answers are/ (b) climate refers to long term atmospheric,conditions weather refers to short term.