[Solved] Fine-grained igneous rocks (grains < 1.0 mm) that have small grains cooled rapidly and are likely to be _______. A) extrusive B) reclusive C) intrusive D) obtrusive E) preclusive Mucus: A sticky, slimy substance produced by mucous membranes and glands designed to moisturize and protect certain parts of the body, such as the nose and throat. Specimen Testing: The analysis of a sample of body tissue or fluid to diagnose or monitor health conditions. Microscopic Examination: The analysis of small objects or structures that cannot be seen with the naked eye, using a microscope. Epithelial Cells: Cells that line the surfaces of the body, such as skin, blood vessels, urinary tract, and organs, providing protection, absorption, and secretion functions.