Cepheids: brighten and dim periodically
can be used to measure stellar distance
have been discovered in galaxies other than our own
all of the above

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.

the fossil record provides evidence of a common ancestor to many species.

answerconditioned response;