An unknown brown solid material was melted and then allowed to cool. it did not separate into different substances. is the unknown material a mixture or a pure substance?

i think the unknown solid is

Adigestive system that is a series of tubes beginning at the mouth and ending at the anus is a digestive system.

Step 1 review the imaginary strand of dna below. note the complementary base pairs. a g c a a t c c g t c t t g g t c g t t a g g c a g a a c c step 2 to begin replicating this strand of dna, draw the two sides of the strand separating. step 3 now, draw the free-floating bases linking up with the separate sides. remember to follow the rules of complementary base pairing. step 4 draw the two resulting dna strands.

Which of these transport mechanisms moves glucose from the blood into a cell? active transport diffusion facilitated diffusion osmosis