1. Kev Taw Qhia: Cov Lus Teb Ncaj Qha Txhawm rau saib xyuas cov dej nyob deb kom zoo, qhov kev daws teeb meem txheem kev lag luam yog ib qho kev sib koom ua ke uas txuas nrog Submersible Hydrostatic Water Level Sensor nrog lub hnub ci zog saib xyuas cov ntaub ntawv ntsuas dej. Qhov kev teeb tsa ywj pheej no ua rau lub sijhawm tiag tiag ...