Which substances compose the backbone of DNA? sugars and lipids
phosphates and amino acids
sugars and phosphates
lipids and proteins

Which statement best describes the role of religion and culture in ancient medicine?

For the strategies below, decide whether they are best described as demand-side solutions or supply-side solutions to meeting human needs for fresh water. remember that a demand-side solution reduces demand for fresh water, whereas a supply-side solution increases the supply of fresh water. (a) damming a river to create a reservoir (b) desalinating seawater (c) a nation invading a neighboring country to access their rivers (d) raising water prices for consumers and businesses (e) providing tax breaks for companies that use less water (f) replacing inefficient irrigation with more-efficient drip irrigation to grow crops (g) requiring low-flow showerheads in all new homes

This is the interaction of two organisms where one is and the other is neither nor harmed.