A.there is a risk of collision B.you are the give-way vessel C.the other vessel is the give-way vessel D.there is no risk of collision
A.推動B.發(fā)展C.支撐D.競爭
A.經陰道超聲B.宮腔鏡檢查C.宮腔造影D.子宮內膜取樣