1. "There is no such thing as private ownership of land" is correct. It sounds strange when you add "a" - maybe because you're trying to single out an example of absolute non-existence. 2. As far as I can tell, this is a poor paraphrase of some classic. There are a couple of mistakes in your example. "It seemed he had quite a lot to talk to me about. He didn't seem to like to finish the talk quickly, as was the case (for) the first time." I understand the last part to mean that they had talked before, but at that earlier time he finished the conversation quickly. This time, he doesn't want to. Having the "for" there is a little confusing. 3. The pattern is "It's high time [subject] [past tense]". It's actually past subjunctive, meaning you are suggesting the action. It's a little difficult to put "had to" in the sentence because it functions as an obligation and not as a basic action. Also, if you use B in the answer, it looks like unnecessary repetition: you've shoved two sentences together, messily.