Explanation:
Osteopetrosis is a condition in which bones become weak and brittle. It causes the body to constantly absorb and replace bone tissue. With osteoporosis, new bone creation doesn't keep up with old bone removal.
While some don't experience symptoms, common symptoms can include bone fracture and a decrease in height.
Most treatments include supplements and diet modifications.
Answer:
Iris
Explanation:
The iris seems to be the illuminated portion of the eyes which really covers the pupil. It controls the amount of light reaching the eye. The lens is indeed a translucent layer of the retina that serves to concentrate light and objects on the lens.
whats that supposed to mean
Answer:
first one is b 2nd one is a 3rd is c and the 4th one is c also
Explanation: have a nice day
(a) 
The frequency of a wave is given by:

where
v is the wave's speed
is the wavelength
For the red laser light in this problem, we have
(speed of light)

Substituting,

(b) 427.6 nm
The wavelength of the wave in the glass is given by

where
is the original wavelength of the wave in air
n = 1.48 is the refractive index of glass
Substituting into the formula,

(c) 
The speed of the wave in the glass is given by

where
is the original speed of the wave in air
n = 1.48 is the refractive index of glass
Substituting into the formula,
