Echelon32

Pg. 479 #16
Along the curve of islands known as the Florida Keys lies a reef of living coral, the only one of a kind in the continental United States. No Error

Pg. 479 #19
In those cities in which public transportation is adequate, fewer traffic problems occur and pedestrians are rarely involved in accidents. No Error

With the first question, the answer is D (a kind). I knew that there was some redundancy there, but I chose C, because I figured that taking out D would result in "the only one of in the continental US". I'm not sure if the SAT usually does this, where you can take out portions and not care about whats left behind.
With the second question, the answer is E (no error). I put B, since I thought maybe "in which" so change to "where". Also, the "in's" seemed unnecessary with 2 in 4 words. I guess the reasoning here is "those cities" can be like "cities" and "cities in which" is grammatically correct.

I'd appreciate any feedback on these two questions.

iin77

first one should be "its kind." You don't necessarily take out the underlined portion, you just change it.

"where" would sound better, but "in which" is grammatically correct, so it doesn't need changed.

gcf101

479/16.
Even though it is rated E, I find it very tricky, not because I am not a native speaker of English - many English native speaking students stumble on this question.

There are two very similar idioms:
one of a kind
and
one of its kind.
"One of a kind" means unique.
"One of its kind" implies that there is a certain category which combines a number of similar objects, and only one of them is mentioned in the sentence.

Certain reefs of living coral belong to a specific kind, and there is a number of them in different parts of the world, but in the United States there is only one reef of this kind - along the Florida Keys Islands.
A giveaway in this sentence is "THE ONLY ONE", which suggests that there exist more reefs of this particular kind - of "its kind".