$a in string no longer required. Changed the text slightly to make it make some sense.
Merged from STABLE_19
$string['displaydefaultfeedback'] = 'Display default feedback';
$string['displayhighscores'] = 'Display high scores';
$string['displayinleftmenu'] = 'Display in left menu?';
-$string['displayleftif'] = 'and only display if $a has grade greater than:';
+$string['displayleftif'] = 'Display left menu only if grade greater than:';
$string['displayleftmenu'] = 'Display left menu';
$string['displayofgrade'] = 'Display of grade (for students only)';
$string['displayreview'] = 'Display review button';