禽流感经空气传播、候鸟传播，存在极大的不确定性，不可防不可控，只有接种疫苗后听之任之。

A、酸性气体排放、大气氢离子浓度、酸性气体减排 Acid gas emissions, atmospheric hydrogen ion concentrations, reduction of acid gases
B、重金属排放、土壤重金属浓度、重金属废物回收量 Heavy metal emissions, heavy metal concentrations in soil, recovery of heavy metal scraps
C、氮排放量、水体内氮浓度、除氮设备投资 Nitrogen emissions, nitrogen concentration in water, investment on nitrogen removal equipment
D、温室气体排放、大气温室气体浓度、能源消耗强度 GHGs emissions, atmospheric GHGs concentration, energy consumption intensity

A.＞1.0g/d
B.＞2.0g/d
C.＞3.0g/d
D.＞3.5g/d
E.＞4.0g/d