Blue Book Writing, pg 480 #25, 28

<p>Please explain, thank you!</p>

<ol>
<li><p>This is kinda like an idiom type question. You have a preoccupation IN technique and not ON technique. Just something you have to memorize</p></li>
<li><p>"its" is incorrect because "its" is for a singular subject. However, the subject, "tabletS", is plural. The correct answer should be "their"</p></li>
</ol>