Answer:
the element oxygen , represented by the symbol o, is classified as a pure substance
The<em> cell membrane</em> controls the movement of substances in and out of cells and organelles. In this way, it is selectively permeable to ions and organic molecules.
The two basic reaction types are synthesis and decomposition. ... Decomposition reactions are the opposite of synthesis reactions because they take apart larger molecules and/or compounds. The generic equation for a synthesis reaction is A + B à AB, where A and B are the pieces that make up the compound/molecule AB.
The correct answers are 2. arid climate and 4. oil resources
The climate always causes environmental climate, especially arid one, while oil both extraction and production creates environmental problems.
