Why don't ecosystems systems exist between fresh and salt water systems?

Which class of molecules contains the amino group, nh2 (a) sugars (b) water (c) proteins (d) hydrocarbons

For a comparative or experimental investigation, scientists often make a testable about a scientific question, and then they test it in the investigation. a.control b.hypothesis c.procedure d.system

The mammal pictured below is a silvery mole rat. which statement is an inference based on the picture? the animal is ugly. the animal has hairless feet with sharp claws. the animal has prominent upper and lower incisor teeth. the animal likely has poor vision since its eyes are so small.