<span>they have to be selective permeable to filter out the waste products but allow the nutrients and blood cells to pass through. </span>
Answer:
1). 
2). Toward us
3). 
4). Toward us
5). 
6). Away from us
7). 
8). Away from us
Explanation:
Spectral lines will be shifted to the blue part of the spectrum if the source of the observed light is moving toward the observer, or to the red part of the spectrum when it is moving away from the observer (that is known as the Doppler effect).
The wavelength at rest is 121.6 nm (
)

Then, for this particular case it is gotten:
Star 1: 
Star 2:
Star 3:
Star 4:
Star 1:
Toward us
Star 2:
Toward us
Star 3:

Away from us
Star 4:

Away from us
Due to that shift the velocity of the star can be determine by means of Doppler velocity.
(1)
Where
is the wavelength shift,
is the wavelength at rest, v is the velocity of the source and c is the speed of light.
(2)
<em>Case for star 1
:</em>
<em></em>
Notice that the negative velocity means that is approaching to the observer.
<em>Case for star 2
:</em>
<em>Case for star 3
:</em>
<em>Case for star 4
:</em>
Ozone is a molecule that consists of three oxygen atoms. When high-energy ultraviolet rays strike ordinary oxygen molecules (O2), they split the molecule into two single oxygen atoms, known as atomic oxygen. A freed oxygen atom then combines with another oxygen molecule to form a molecule of ozone. Hydrocarbons and nitrogen oxides come from great variety of industrial and combustion processes. Motor vehicle exhaust and industrial emissions, gasoline vapors, and chemical solvents are some of the major sources of NOx and VOC that acts as a precursor of ozone. In urban areas, the number of automobiles are more and therefore, more production of such harmful gases. These gases in presence of sunlight leads to the formation of bad ozone.
Answer:
its In most solids, conduction takes place as particles vibrate in place.
Explanation:
i did it in a test