A.小于水頭的1/5 B.大于水頭的1/5 C.小于水頭的1/4 D.大于水頭的1/4
A.大于320mm B.小于300mm C.大于300mm D.小于320mm
A.95%~96% B.96%~98% C.96%~100% D.98%~100%