Not positive contact的意思|示意

It is known that when CB1 comes into contact with cannabis it has an impact on bone regeneration, but until now it was not clear whether the drug had a positive or negative effect.

已经知道CB1和大麻接触后将对骨再生产生影响，但尚未清楚它是正效应还是负效应。

USE: Electric- contact pressure gauges are used for measuring positive and negative pressure of liquids and gases which are nor corrosive to copper and copper alloy and not explosive and crystal.

电接点压力表适用于测量对铜及铜合金无腐蚀、无爆炸危险、非结晶的各种液体、气体等介质的压力。