Which statement is correct? a Star formation begins in the nebula
b White dwarfs become main-sequence stars when they gain mass
c Supergiants are stars that can absorb black holes
d Main-sequence stars are formed by comets

explanation:

could i give you a exaplo that could you?

c)as speed changes, wavelength and frequency change.

everything changes!

this is an example of "committed" time.

committed time, as contracted time, takes need over essential and available time since it is seen as profitable work. it alludes to the time allotted to keep up a home and family. at the point when a man is commuting using committed time this individual may feel that the drive is an obligation to family, for example, strolling youngsters to class or driving a mate to work. contracted and committed time clients may feel that their commute could really compare to the commute of important or leisure time clients on the grounds that their commute is profitable work. in this manner, they might be more disposed to pick a mechanized method of movement.