请问下面这句话中的be on safer ground 是什么意思？
\u5173\u4e8e\u94a2\u710a\u63a5 all welds on mounting ground furface must be ground flush \u4ec0\u4e48\u610f\u601d\uff1f\u5c31\u662f\u5b89\u88c5\u5e73\u9762\u7684\u710a\u7f1d\u5fc5\u987b\u5e73\u9f50\uff0c\uff08\u5982\u679c\u4e0d\u5e73\uff0c\u53ef\u4ee5\u6253\u78e8\u4e4b\u7c7b\u7684\uff09
\u8981\u6c42\u91c7\u7eb3
on the ground
\u5728\u73b0\u573a\uff1b\u5f53\u573a\uff1b \u5728\u8fdb\u884c\u51b3\u6597\uff1b\u5728\u5730\u4e0a
on the grounds
\u7531\u4e8e...\u7684\u539f\u56e0
on the grounds of\u57fa\u4e8e\u2026\u2026\u7406\u7531\uff0c\u6839\u636e(=on the basis of, in the light of,)
on the grounds that conj. \u7531\u4e8e\uff08\u6839\u636e\uff09(since, now, seeing)
on the grounds of /that\u7406\u7531\u662f
地面安全
扩展阅读：be on的用法 ... be on翻译 ... be onto something big ... in on在树上口诀 ... be in和be on的区别 ... bed 前面是on还是in ... be on什么意思 ... be on的中文意思 ... be over是什么意思 ...
