Which of these buildings is most likely to have indoor air pollution

The building from the list provided with the highest likelihood of air pollution is a tightly sealed house with an unvented water heater. The school with leaks will let air exchange happen so that isn't it, and having a carbon monoxide detector only reports existing air pollution it doesn't prevent air pollution, it could have issues but we don't know. The tightly sealed house with the unvented water heater is a near sure thing.

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

The answer to this will be from your lab notes/procedure. it would be best to ask another student who participated in the lab as we do not know what was done, what enzyme or if the temperature is celsius or fahrenheit. if i were to guess though i'd say the rate stopped due to enzyme denturing at high temperature