A case control study of the association between an exposure and a disease is characterized by: a. Assessment of the exposure and disease at the same point in time
b. Exclusion of all individuals who currently have the disease
c. Exclusion of all individuals who have been exposed in the past
d. Follow-up of exposed and unexposed groups for future onset of the disease
e. Assessment of past exposure in groups with and without the disease

In a water molecule, hydrogen and oxygen are held together by a(an) bond. a) double covalent b) ionic c) nonpolar covalent d) hydrogen e) polar covalent

Which of the following units is not an official si unit

Pegmatites are igneous rocks in which the individual minerals are very large. typically, the minerals are all light-colored quartz, feldspar and muscovite. if you were given a black and white photograph of a pegmatite in a quarry (where the rock has been blasted and broken), what physical properties could you use to identify those three minerals in this hypothetical photo? describe each mineral and the specific diagnostic properties. be specific.