Answer:
The spectral types and sub-classes represent a temperature sequence, from hotter (O stars) to cooler (M stars), and from hotter (subclass 0) to cooler (subclass 9). The temperature defines the star's "color" and surface brightness. ... Stars are also classified by luminosity class.
Explanation:
<span>im pretty sure it is Sisak.</span>
Answer: Options A, B and D.
Explanation: shields are layers of old rocks that metamorphosed as a result of mountain-building events. Shields also have sedimentary layers that usually rest on the lava of the rock.