Errors of ________ occur when the eyeball is either too long or too short, the lens loses its elasticity, or the lens or cornea has an irregular curvature

Neurons in the spinal cord descending tracts are known as:

a. Upper motor neurons b. Lower motor neurons c. Neither; they are sensory neurons

Which of the following is an additional grease-removal device present in some exhaust systems that may present a fire hazard due to accumulation of grease on filters?

A. Extractor B. Detractor C. Single exhaust duct D. Manifold exhaust duct system