SAT Writing Questions. Please help?

<p>I’m not realy sure if I’m even allowed to ask these questions here, but I really need help.</p>

<p>These two writing questions are from the Jan. 08 test.</p>

<li>No one but a fool would readily lend money to a person who is known to be a frequent gambler. No error.</li>
</ol>

<p>The answer is no error.
I was wondering if anyone can explain the different between ‘to be’ and ‘as’.
When to use which? And what’s the difference?</p>

<li>For any mayor of a vast metropolitan area, an understanding of current issues in all districts is not only desirous but also vital. No error.</li>
</ol>

<p>The answer is ‘desirous’.
Is it because it should be desired?
Can someone please explain the different between ‘desirous’ and ‘desired’?</p>

<p>1.) "to be" works better in this because this sentence is attempting to convey the state of the person who's a frequent gambler. </p>

<p>2.) Desirable. Is 'desirous' even a word? </p>

<p>Sorry if my explanations suck. I got an 800 writing, but I don't really know grammar -- I just know what sounds wrong :P</p>

<ol>
<li><p>If there's nothing wrong with it, don't change it. "As" slightly changes the meaning (suggesting maybe he is only known for his gambling), and while it is grammatically correct, so is "To be".</p></li>
<li><p>Look up 'desirous' in the dictionary - this is a 'trap' word.</p></li>
</ol>

<p>thanks guys. =]</p>

<p>So I guess for #1, 'to be' is more factual than 'as' in a way?</p>

<p>However according to desirous</a> - Definitions from Dictionary.com
desirous is a word? Or are online dictionaries not trustworthy?</p>