What are humans dogs and whales homologous structures or analogous structures

Why do mountaineers become breathless as they reach high altitudes

What are polysaccharides more difficult to digest than monosaccharides

Select all the correct answers. for a claim about the natural world to be considered scientific, what attributes must it have? a).it must be applicable to future events and occurrences. b)it must be based on scientific observations that can be repeated in a controlled setting. c)it must be open to modification if new evidence doesn't completely support it. d)it must be consistent with only a small portion of relevant observations or data.