A.difference between the true course and the compass course B.momentum of a vessel after her engines have been stopped C.lateral movement of a vessel downwind of her intended course D.displacement of a vessel multiplied by her speed
A.O1群小川型和O139群交替流行B.甲魚等海水產(chǎn)品為常見(jiàn)感染來(lái)源C.以散發(fā)病例為主D.多為食源性傳播E.流行強(qiáng)度較低