Somebody can help me solve these difficult Grammer questions?

<p>Below are some grammer questions,and i cannot figure out the answer.
I really hope someone can help me to let me get rid of the nightmare-like SAT grammer.
Thank you!</p>

<p>Mediators were standing by, prepared to intervene in the labor dispute even both sides had refused earlier offers for assistance.</p>

<p>The correct anwer is to choose for, but i think it is right.</p>

<p>Quincy took Dan to Derek’s home for a visit, never imagining that five years would pass before seeing Derek again. </p>

<p>The correct answer is to choose seeing, but i dont know what is wrong.</p>

<p>When the Berlin Wall, long a symbol of the Cold War, began to be torn down in 1989, five million people went to Berlin to celebrate that.</p>

<p>A. to celebrate that
B. for its celebration
C. to celebrate
D. in celebration of that
E. in celebrating</p>

<p>the correct answer is to choose c, although i choose c, but i think b is also correct.</p>

<p>When Doris Lessing published The Golden Notebook in 1962, it instantly established herself as one of the most important literary voices of her generation. </p>

<p>the correct is to choose it, but i cannot find its grammatical failure.</p>

<p>Grammar becomes easier if you spell it right</p>

<p>
[quote]
Mediators were standing by, prepared to intervene in the labor dispute even both sides had refused earlier offers for assistance.

[/quote]
</p>

<p>I think they probably want "offers of assistance" instead of "offers for assistance."</p>

<p>
[quote]
Quincy took Dan to Derek’s home for a visit, never imagining that five years would pass before seeing Derek again.

[/quote]
</p>

<p>Who's doing the seeing? It isn't clear. It would be better to say "...five years would pass before Quincy saw Derek again" or even "...five years would pass before he saw Derek again."</p>

<p>
[quote]
When the Berlin Wall, long a symbol of the Cold War, began to be torn down in 1989, five million people went to Berlin to celebrate that.

[/quote]
</p>

<p>What does "that" refer to? It doesn't seem to have a clear antecedent. Choice B, "for its celebration," has the same problem -- what does "its" refer to? These unclear references aren't necessary, so just leave them out.</p>

<p>
[quote]
When Doris Lessing published The Golden Notebook in 1962, it instantly established herself as one of the most important literary voices of her generation.

[/quote]
</p>

<p>Similar problem as the previous sentence. What does "it" refer to? Notice "herself" a couple of words later, so "it" must be referring to Doris Lessing, but you wouldn't use "it" to refer to a person. I think it needs to be "she instantly established herself."</p>

<p>If the sentence had said "her" instead of "herself," then I still would have changed "it" to say something like "its publication instantly established her ..." because otherwise it isn't crystal-clear what "it" is referring to.</p>

<p>Many thanks!</p>