Where in a river would you find fish that are adapted to low light and low oxygen levels?

at the source

in the midriver

near the mouth

no place in the river is characterized like this.

Explain what it means to view something from a frame of reference. provide an example that illustrates your explanation. (4 points)

A5 foot by 5 foot box culvert is buried 6 feet beneath the surface of the ground. a crosssection of this very long culvert (into and out of the page) is illustrated below. assume that the soil in which the culvert is buried has the following properties: jt = 120 pcf, w = 12%, ko = 0.50, ka = 0.33, and kp = 3.00. calculate the total horizontal force per unit length of culvert (fh) felt on one of the vertical faces of the culvert.

Calculate a pendulums frequency of oscillation (in hz) if the pendulum completes one cycle in 0.5s.