You are a research scientist trying to determine if the genes controlling bone density can be affected by environmental factors. What would be most useful to your research?
A. X-ray machine
B. Siblings to study
C. Mass Spectrometer
D. Identical twins to study

answer; /// the correct )

explanation:

for  example, forests have higher evapotranspiration than other ecosystems,  such  as grasslands, because of their deeper roots and greater leaf area. thus forests have a net moistening effect on the atmosphere and become a moisture source for downwind ecosystems.

hydrogen is a compound or a single element and a element is a pure substence that cannot be separated into simpler subtances

clorine is a compound its a chemical substance that forms when two or more different elements combine

so both hydrogen and clorine are compounds