Indoor plumbing, medical advances, and improved personal hygiene practices have A human life expectancy.

The light is great source of energy

1) clean up you lab area2) dispose of the chemicals as instructed by your teacher3) put everything back where it belongs unless your teacher tells you otherwise4) dispose of gloves5) wash hands with soap and water

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

D. peatlands,grassland,swamps