Which of the following statement(s) is/are TRUE regarding lashing requirements to secure vehicles aboard Ro-Ro vessels? （） It is imperative that the securing of cargo on flats and trailers and in containers be adequate for both road and sea motions。 The movements experienced by road borne cargo differ significantly from the roll and sway movements of a ship at sea。 It is necessary for adequate number and strength of securing points on the vehicles themselves in order that lashings may be properly and safely utilized.。 All the above。
简述簇管虫的病源。
Which of the following will be desirable properties of refrigerant?（） (1) non-explosive (2) non-corrosive (3) that it doesn’t react with lubricants (1), (2) and (3)。 (1) and (2)。 (1) and (3)。 (2) and (3)。
下列项目投资决策评价指标中，其数值越小越好的指标是（） 内含报酬率。 投资回收期。 获利指数。 平均会计收益率。
造成食物链缩短的有：（） 稻田养鱼。 围湖造田。 开垦草原。 砍伐森林。
零存整取存款期限没有（）。
