<p>why is the answer not "A" on p 479 # 19? shoudlnt it be "In those cities WHERE..."?</p>
<p>It could be "where," but there is nothing wrong with "in which." (Remember that if the original is not wrong grammatically, you can't choose it just because there is an alternative. Style is NOT tested on the Identifying Sentence Errors questions.) You're simply saying that public transportation is adequate IN those cities. Therefore, it's E, no error.</p>
<p>Also, there is not a specific location for the public transport... "where" refers to specific locations. While "where" could be interpreted as referring to the cities themselves, it's a bit of a stretch. Godot is right on when he says that public transport is usually described as "in" cities.</p>