What are the blood vessels called that carry blood to the heart?.

What links the two strands in a dna helix together in the middle? a. phosphate groups b. sugar rings bonded together c. proteins d. bases with hydrogen bonds

What kind of crystalline solid is graphite? o a. molecular solid b. metallic solid o c. network solid d. ionic solid

Each pair of clay balls represents two planetesimals. if each planetesimal is composed of the same material and is separated he the same distance, which pair experiences the frayed gravitational attraction?