A.privileged vessel and would sound two short blasts
B.burdened vessel and would sound two prolonged blasts followed by two short blasts
C.burdened vessel and would sound no whistle signal
D.privileged vessel and would sound no whistle signal
A.異常子宮出血
B.IUD及宮內(nèi)異物定位,試取
C.宮腔黏連
D.以上均是