D Answer each question. 1. What is the range of frequencies a human ear can hear?
2. What is the speed of sound?
3. Whích two animals locate things by echoes?
nitch of your voice?

Step-by-step explanation:

1. Humans can detect sounds in a frequency range from about 20 Hz to 20 kHz.

2. speed of sound is 343 m/sec.

3. two animals are Bats and Whales.

4.The voiced speech of a typical adult male will have a fundamental frequency from 85 to 180 Hz, and that of a typical adult female from 165 to 255 Hz.

the system of inequalities is

step-by-step explanation:

step 1

find the equation of the dashed line

we have the points

(0,0) and (3,1)

the line passes through the origin, so, is a direct variation

find the slope

the equation of the dashed line is

the solution of the inequality a s the shaded area above the dashed line

therefore

the equation of the inequality a is

step 2

find the equation of the solid line

we have the points

(4,0) and (0,4)

find the slope

the equation of the solid line is

the solution of the inequality b s the shaded area below the solid line

therefore

the equation of the inequality b is

step 3

the system of inequalities is

2x + 8

step-by-step explanation: