TENS

"Half this number is less than 6 times the tens dight of the number by 4."

这个数值一半比它十位数值6陪小于4.

For general exploringobjects requirement, narrow pulse signal with tens millimicro second to millimicrosecond has the frequency spectrum from DC to thousands MHz.

按照对地目标探测一般需要,通常采用纳秒到十纳秒电磁探测窄脉冲,信号频谱有从直流低频直到千兆赫带。

Overpumping groundwater for drinking water and irrigation has caused water levels to decline by tens of metres in many regions, forcing people to use low-quality water for drinking.

过度抽取地下水做为饮用水和用来灌溉在许多地区已经使水位下降了几十米，迫使人们使用质较差水来做为饮水。