acoustic zero level的用法和样例：
- Green segregating construction market level will increase land supply for the market to curb land speculation zero level, lower land costs.
- For chromium level, apparent energy, protein and fat metabolizability were elevated much more by 0.4 and 4mg/kg level (p<0.05) than zero level at six weeks and apparent fat metabolizability by 4mg/kg than 0.4mg/kg.
- The zero level of corresponding point is subtracted from sampled value to eliminate the zero fluctuation and multiplied by compensating coefficient to modify the sensitivity fluctuation.
- zero level transmission reference