[单选] The place where a channel moves from along one bank of the river over to the other bank of the river is called a（）.

Under MARPOL Code the ship to which it applies has to carry （） an International Ship Security Certificate。 an International Oil Pollution Certificate。 a Safety Management Certificate。 an International Ballast Water Management Certificate。 The presence of stratus clouds and a dying wind will usually result in（）. heavy rain。 heavy snow。 thick fog。 clearing skie。 CDMA系统无线链路中有导频信道、同步信道、寻呼信道和业务信道，其中寻呼信道和正向业务信道的数量分别是（）。 最多有7个和最多有55个。 必须有7个和最多有55个。 最多有7个和必须有55个。 必须有7个和必须有55个。 Under ISM Code the ship to which it applies has to carry （） an International Ship Security Certificate。 an International Oil Pollution Prevention Certificate。 a Safety Management Certificate。 an International Ballast Water Management Certificate。 根据预防伤亡事故的原理简述事故的预防对策？ The place where a channel moves from along one bank of the river over to the other bank of the river is called a（）.