<p>Blue Book:</p>
<p>p 602 # 14</p>
<p>Because they painted scenes of life as ordinary people lived it, rather than scenes from myths many nineteenth-century American artists differed from earlier times.</p>
<h1>16</h1>
<p>.... each of them ate many times its own weight...</p>
<p>Would you use "their" if it said "all of them"?</p>