How many planets do we have​

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.

When analyzing tree rings, what do scientists assume a thin ring indicates?

Which statement names a physical property of wood? wood does not rustwood can burnwood can rotwood is softer than coal