Approval.

zh/units_length_set.php

@@ -1,2 +1,10 @@
 <?PHP
 declare(strict_types = 1);
+$units_length_set = array (
+  'm' => '公尺',
+  'dm' => '分米',
+  'cm' => '公分',
+  'mm' => '公厘',
+  'ft' => 'ft',
+  'in' => 'inch',
+);