Vitamin d regulates the absorption of from the small intestine. calcium and fluoride phosphorus and magnesium calcium and magnesium calcium and phosphorus

6. in the dna double helix, how are the two strands of dna held together? a. chemical bonds between base pairs hold the two strands of dna together. b. hydrogen bonds between the base pairs hold the two strands of dna together. c. hydrogen bonds between sugar groups and phosphate groups hold the two strands of dna together. d. chemical bonds between sugar groups and phosphate groups hold the two strands of dna together.

Which term best describes a community in which people work mostly in factories? a. agricultural. b. hunting and gathering. c. domesticated. industrial.

Construct at least two possible hypotheses for the student’s experiment.