[单选题]根据血清分型,免疫球蛋白可分为A.同种型、同种异型、独特型B.同体型、同种异型、独特型C.同体型、同体异型、独特型D.同种型、同体异型、独特型E.独特型、同种型、同体型
[多选题]川航的企业宗旨是( ).A.服务社会B.旅客至上C.创造效益D.创造效率E.树立信誉
[单选题]关于牵涉痛,正确的说法是( ).A、牵拉引起的疼痛B、深部痛C、浅表痛D、持续痛E、内脏痛而引起特定体表区的疼痛
[单选题]第二组Displacement pumps are those where the volume of the pump chamber is alternately increased to draw the liquid in from the suction pipe and then decreased to force the liquid out into the delivery pipe. Centrifugal pumps are those wherein an impeller rotating at high speed throws the liquid by centrifugal force from the center to the periphery of the impeller where the liquid is discharged through the delivery outlet.Gear pump consists of two or more meshing gears (spur, single or double helical teeth) enclosed m a close-fitted housing. These are used extensively for pumping fuel oil, lubricating oil and hydraulic oil. When gears are unmeshed on the inlet side, a pressure drop occurs that helps the atmospheric pressure acting on the surface of the oil in the reservoir to force it up the pipe to fill the void, the oil is then transferred around the periphery of the pump housing. As the gear teeth mesh again on the outlet side, they form. a seal that prevents oil from backing up to the inlet, the oil in the void is then be forced out into the discharge line.All vane pumps have a rotor driven within a ring (cam ring) by a drive shaft coupled to a prime mover. A cylindrical rotor with sliding vanes, generally in radial slots, rotates within the ring. The center of the rotor is offset from the center of the ring. In a simple vane pump, as the rotor turns, the vanes are forced outward against the inner surface of the cam ring by centrifugal force. This outward radial movement of the vanes and turning of the rotor causes the chamber between the vanes to increase as the vanes pass further away from the inlet port. This increase in volume results in a lowering of pressure until the atmospheric pressure is sufficient to force oil from the reservoir into the inlet chamber. Oil from the inlet is swept away by the vanes toward the outlet port through a decreasing series of chambers until it is forced through the outlet port. A vane pump of balanced design has an elliptical cam ring so that two pumping chambers are formed. This pump is in hydraulically balance, since the two intake and two outlet ports are diametrically opposed to each other. Therefore the side loads exerted on the rotor cancel out, thereby increasing bearing lift and permitting high operating pressure.According to the last sentence of paragraph 1, from where the liquid is discharged through the delivery outletA.from the eye of the impellerB.from passage of impellerC.from the periphery of the impellerD.from the impeller
[单选题]In order to limit the introduction of alien species by ship, ____was adopted on 13 Feb, 2004 at the IMO.A.Revised MARPOL annex IB.Revised MARPOL annex IIC.International convention for the control and management of ships’ ballast water and sedimentsD.ISPS Code
[单选题]非本船人员进人机舱,须经＿准许.A.船长B.轮机长C.值班人员D.船东代表
[单选题]某些套管式活塞冷却机构中设有空气室,其作用是________.A.释放水中的空气B.防止腐蚀C.缓冲防水击D.保证稳定供水
[单选题]内生肌酐清除率的正常值是A.40～50ml/minB.50～60ml/minC.70～80ml/minD.80～120ml/minE.120～150ml/min
[单选题]除高速船以外的特种船培训合格证有效期为_______年.A.2B.3C.4D.5
[单选题]自身抗体中,以第一位检出该抗体的患者命名的抗体包括A.抗SSA抗体B.抗RNP抗体C.抗DNP抗体D.抗Ro抗体E.抗dsDNA抗体
[单选题]在资产定价模型中用来测度不可消除系统性风险的是( ).A.阿尔法系数B.贝塔系数C.资产收益率D.到期收益率
[单选题]以下关于空值(NULL)叙述正确的是A.空值等同于空字符串B.空值表示字段或变量还没有确定值C.VFP不支持空值D.空值等同于数值0
[单选题]下列组件不能添加进Frame主窗口的是A.PanelB.CheckBoxC.DialogD.Choice
[单选题]以下不属于扁骨的是A、颅骨B、胸骨C、肩胛骨D、肋骨E、股骨
[单选题]执行如下语句: a = InputBox( Today, Tomorrow, Yesterday,,, Day before yesterday, 5) 将显示一个输入对话框时,在对话框的输入区中显示的信息是 ______.A.TodayB.TomorrowC.YesterdayD.Day before yesterday
[单选题]严格定义的方法是在一定假设的前提下形成的,它认为系统的所有需求都能够被( ).A.确定无误B.即时变化C.事先定义D.随时更改
[单选题]主要Ig的特性和功能中,血清Ig升高说明有近期感染属于A.IgGB.IgMC.IgAD.IgDE.IgE
[单选题]慢性硬化性肾小球肾炎的尿液变化是( )A、蛋白尿B、少尿、无尿C、多尿、夜尿D、管型尿E、血尿
[单选题]劳之为病,其脉浮大,手足烦,春夏剧,秋冬瘥,阴寒精自出,酸削不能行,属于哪种类型的虚劳病（)A、阴虚B、阳虚C、血虚D、阴阳两虚E、气血两虚
[单选题]血细胞分析仪白细胞直方图中中性粒细胞峰右侧区域异常原因有A.可能存在血小板聚集现象B.可能存在有核红细胞C.可能存在中性粒细胞绝对值增多D.可能有巨大血小板增多现象E.可能有异型淋巴细胞
[单选题]摩托车四年以内每( )检验一次,超过四年的,每年检验一次.A.1年B.2年C.半年D.规定的期限