What type of energy is present when lightning strikes? a. electrical energy b. chemical energy c. nuclear energy d. gravitational energy

Patricia is told by her physician that her body and brain chemistry have physically adapted to the drug and that she has become dependent on the tranquilizers prescribed for her by another doctor.

Which kind of worm has a closed circulatory system? a planarian b fluke c pinworm d an earthworm

Number and variety of living organism; includes genetic, species, and ecological types