ACT Scoring Question - how do two 18s equal a 35?

<p>My D got her ACT scores back and I don't understand some of the scoring. Can anyone help?</p>

<p>English - 35
Usage/Mechanics: 18
Rhetorical Skills: 18</p>

<p>(Don't two 18s equal 36?)</p>

<p>Reading: 33
Social Studies/Sciences: 17
Arts/Literature: 17</p>

<p>(Same question - why not 35? I get that there may be a downward curve, but that doesn't explain the English score.)</p>

<p>Thanks!!</p>