7. The Cuyahoga River in Ohio has caught fire eleven times. The last time was in 1969, when
sparks from a train are believed to have ignited
an oil slick on the river. The condition of the
Cuyahoga River most likely helped persuade
Congress to pass which act?

A. the Wilderness Act

B. the Clean Water Act

C. the Flood Control and Coastal Emergency
Act

D. the Marine Protection, Research, and
Sanctuaries Act

answer: the correct answer for the fill in the blank is rods.

rods are the specialized photoreceptor cells that are present in the retina of human eye. they are responsible for vision in the night time ( also called scotopic vision). they have very low visual acuity and color distinguishing ability.

as they are responsible for vision in night time, therefore they are found predominantly in the nocturnal animals.