#1: First of all, the sentence itself is already incorrect. Instead of "birth" it should say "birthplace". As for the word in the blank, I think both A and C are acceptable, but if I had to choose, I'd choose A. I'm not sure I can explain why. I would say that B is unacceptable because if you were to restructure the sentence as "kite flying spread to Japan, etc, ________ " and put the original location in the blank, it requires the preposition "from": that is, "from China". So when you restructure it into a subordinate clause like this, it has to start with the preposition "from". I think A is correct because "which" better refers to a neuter, unspecified noun, which is what we have here. It refers back to the noun phrase "the birthplace of kites". Suppose instead the sentence was like this. "We went to China, from where we then travelled to Mongolia." In that case, "from where" is preferable because the antecedent noun is a place, "China". In the example above, the antecedent noun is not a place, it's a noun phrase (that incidentally refers to a place). It's a very subtle point, and I don't think it even really matters whether you choose A or C in #1. Just not B. #2. D. Definitely. In this case, all of the answers that start with a preposition are incorrect. It's basically the same as the sentence, "Make a mark here." The verb "mark" takes a direct object without any preposition. The entire phrase "where you have any questions...passage" is the direct object (phrase) of the verb "mark". Since "mark" requires no preposition, we don't put one in the blank space in #2.

A D Am I right?

1. C 2. D

A