When are expert judges needed to determine the content validity of a test? a. always b. when the trait being measures is ill-defined c. when the trait being measured is highly technical d. all of the above?

The following image is of a diatom. it lives in water and gets food from photosynthesis. it is encased in a hard shell made of something similar to glass or sand . a diatom is a(n) because it has a) multi-celled organism; specialized parts. b) vertebrate; a skeleton. c) insect; an exoskeleton. d) single-called organism; only one cell.

Coral reefs support more species per unit area than any other marine environment on earth. what is one way coral reefs are important to the health of the biosphere

Reactants undergo chemical reaction to form products. this chemical equation represents one such reaction. the coefficient for one of the reactants or products is incorrect. which part of the chemical equation is incorrect?