The general notation for your subtopics in an outline is

The question is asking to state what could be the general notation for the sub topics in an outline and base on my research and further investigation, the possible answer would be roman numerals for the top level, upper-case letters (in the alphabet of the language being used) for the next level, Arabic numerals for the next level, and then lowercase letters for the next level

The sentence needs a descriptor of exactly "what" will happen at gurley and marina. in this case, it is the light at the intersection turning green. in this case, the sentence could be rewritten as "the light at the intersection of gurley and montezuma will turn green exactly three seconds after the light at the intersection of gurley and marina."