Answer:
A. When two tectonic plates start to push into each other they can rise up and build mountains, or sink under and create deep valleys.
Explanation:
It is true
What exercise? Post a picture of it.
Answer:
(1) they keep toxic substances out of the cell.
(2) they contain receptors and channels that allow specific molecules, such as ions, nutrients, wastes, and metabolic products, that mediate cellular and extracellular activities to pass between organelles