bacteria are classified into 5 groups, spherical (cocci), rod (bacilli), spiral (spirilla), comma (vibrios) or corkscrew (spirochaetes).
A type of strong chemical bond in which two atoms share one or more pairs of valence electrons. Two or more atoms held together by covalent bonds. The attraction that exists between opposing (positive and negative) charges within the atom.
Answer:
When the diaphragm contracts (it's a large flat muscle), it pulls the lungs down this causing expansion which eventually lead to inhalation of air. If it's injured, then that will be affected.
Limestone is composed largely of the minerals calcite or aragonite. Some limestones do not consist of grains and are formed by the chemical precipitation of calcite or aragonite. This is how limestone can be classified as chemical.