A ≤15cfu/m<img border="0" alt="" src="https://img.weimei168.com/uploads/upimg/20221202/13376437_0.gif"> B
≤10cfu/m<img border="0" alt="" src="https://img.weimei168.com/uploads/upimg/20221202/13376437_0_1.gif"> C
≤5cfu/m<img border="0" alt="" src="https://img.weimei168.com/uploads/upimg/20221202/13376437_0_2.gif"> D
≤0.5cfu/m<img border="0" alt="" src="https://img.weimei168.com/uploads/upimg/20221202/13376437_0_3.gif"> E
≥0.05cfu/m<img border="0" alt="" src="https://img.weimei168.com/uploads/upimg/20221202/13376437_0_4.gif">