单选21.仪表精度等级的数字小，说明仪表的精度（   ）。

A、<span style="font-size:16px;font-family:宋体">高</span><span style="font-size:16px;font-family:&#39;Times New Roman&#39;,&#39;serif&#39;">&nbsp; &nbsp;&nbsp;</span>

B、<span style="font-size:16px;font-family:宋体">低</span><span style="font-size:16px;font-family:&#39;Times New Roman&#39;,&#39;serif&#39;">&nbsp; &nbsp;&nbsp;</span>

C、<span style="font-size:16px;font-family:宋体">不变</span><span style="font-size:16px;font-family:&#39;Times New Roman&#39;,&#39;serif&#39;">&nbsp; &nbsp; &nbsp;</span>

D、<span style="font-size:16px;font-family:宋体">无法判断</span>