SAT QOD and improper idioms

<p><a href="https://sat.collegeboard.com/practice/sat-question-of-the-day%5B/url%5D"&gt;https://sat.collegeboard.com/practice/sat-question-of-the-day&lt;/a&gt;&lt;/p>

<p>I don't get why it's an improper idiom. I tried searching idioms before and i cam up with nothing. Idioms are my biggest problem at this point! I checked silvertutrle's guide.</p>

<p>really nobody? I posted this 10 hours ago.</p>

<p>Today, A (also) representing nations B (and other) political entities, C (flags are used) D (to represent) youth groups, athletic competitions, and international bodies. E (No error)</p>

<p>The error in this sentence occurs at (A), where there is an improper idiom. The phrase “in addition to” is needed in place of “also.”</p>

<p>Today, also representing nations and other political entities, flags are used to represent youth groups, athletic competitions, and international bodies.</p>

<p>Usually you don’t use ‘also’ before you actually say anything… Also, as a native English speaker this error JUMPED out at me.</p>