Which of these statements best explains why models are used to study the solar system?

the solar system may be viewed differently using different instruments.
the solar system may be visible on earth only for a short period of time.
the solar system is too large and distant to be viewed by everyone.
the solar system is an imaginary area in space which does not actually exist.

A

yep it's probably A

I just watched such a sad movie I almost cried

Have a great day everyone, and don't watch a sad movie

regulation of gene expression. gene expression can be regulated by various cellular processes with the aim to control the amount and nature of the expressed genes. these regulatory proteins bind to dna and send signals that indirectly control the rate of gene expression

explanation:

the cladogram shown here shows similarities and differences among several classes of vertebrates. anatomically, the four have limb structure as their common ancestor. we might separate the mammals from the other three classes because they a) divergent; do not lay eggs b) identical; are warm-blooded c) varied; a four chambered heart d) homologous; have mammary glands