在开始检测前，检测组件上的所有针形阀都必须关闭。

Before starting test, all needle valves on test kit must be closed.

youdao

龋洞很深，在钻牙前我将给您打一针麻药。

The decay is very deep, so I will use a local anesthetic before drilling.

youdao

龋洞很深，在钻牙前我将给您打一针麻药。

The decay is very deep, so I will use a local anesthetic before drilling.

youdao