52.
Your Answer is
Correct Answer is F
Explanation
According to the meaning of the sentence, the preceding and following sentences are turning relationships, and item F however is a related adverb that can lead a sentence alone, which is correct.
Item G: Although the subject-slave conjunction cannot lead a sentence alone.
Item H: such as is a preposition followed by a word and no sentence can be added.
J item: yes is an expression that is too colloquial.