It is unfair to accuse us of trying to get out of answering questions. We happily answer questions about the English language. Unfortunately, your piece had all the hallmarks of a piece of homework - we are frequently given lists of questions to answer and it turns out that it was homework and the student hands in our work instead of their own.
We will always ask a student to give us their answers first and then we comment.
Regarding your original list of sentences, only G is incorrect, because it is not a complete sentence. H will be fine if you remove "through".
Thanks. And sorry about what I said before.
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