How is oxygen conserved as it moves through the ecosystem ?

Based on the topographic map of mt. st. helens, what is the contour interval of the volcano about height is 2,950 m?

Long term exposure to waves can cause sunburns and skin cancer.

Which best describes a benefit of using dna technology in medicine? a) medicine can be produced in mass quantities. b) medicine can be distributed at a reduced cost. c) medicines have fewer side effects. d) medicines are resistant to antibiotics.