I believe the answer is 20 feet. According to McBurney and Collings, the average threshold of human hearing is the tick of a watch from 20 feet in very quiet condition.
The human hearing range is a description of the pitches and loudness levels a person can hear before feeling discomfort. There is a variety of sounds in our environment, ranging from faint sounds like birdsong and rustling leaves to louder sounds like music, yelling, and industrial noise.
Answer:
Explanation:
This is the process of muscle contraction and relaxation in the muscle. The type of muscle involved is the skeleton muscle.
The process is initiated in the Central nervous system. Examples are in contraction of biceps and triceps.
It involves myosin head and actin filament coupled with the release of calcium ion from the sarcoplasm reticulum: this ion activates this process in the muscles. With the exposure of the music binding site on the acting filament, myosin is able to bind to acting filament bringing about this process.
a. ATP attaches to myosin head
b. Myosin head is re-energized
c. Myosin head forms cross bridge with actin
d. Power stroke moves thin filament
e. Cross bridges detach from actin
f. Myosin binding sites covered
g. Calcium ions pumped into the sarcoplasmic reticulum
h. Calcium ion concentration decreases below the threshold for binding to troponin.
<em>Because for example one large eagle needs lots of small sparrows to eat. There is usually a food pyramid so for example you could display it along the lines of 1,000 worms are eaten by 20 sparrows which are eaten by 1 eagle. Its just the way things are. It is a fine balance. if you went up to two eagles on same land they would run out of food quickly and then would either starve or have to move on and using up all the food doesnt help them so it needs to be in a fine balance. A balanced ecosystem.</em>
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A.
Because the light of the sun and the earths orbit make the moon look different sometimes
I think the answer is d.mutation.