When sound passes from one medium to another where its propagation speed is different, which of these change: frequency, wavelength, speed?

Ithink that its like 15 mph.

Single strand binding protein by peptide bond

Are you asking about a street map usage  if so here is your answer  a street map for a very limited area could simply be a bit map or a .jpg image.  but a more general map would probably store the streets as vectors.  but you shouldn't assume that there is one way to do it