What kind of bond holds the sugar-phosphate backbone of DNA together?

Ascientist is designing an investigation to study the impact of invasive bird populations on local, native bird populations at backyard bird feeders. what population is most likely to be a control group for the investigation? amount of food number of bird feeders invasive bird populations local backyard birdfeeders without food

Explain why it’s important for scientists to study the sun. list at least two challenges researchers face when examining earth’s nearest star.

Which of the following can be assumed about the layers in areas 2 and 4