【判断题】螺栓连接在装配时要拧紧螺母,使螺栓连接受到预紧力的作用。
【判断题】紧螺栓连接是指在受到工作载荷作用前螺栓上就已受到较大的轴向拉力作用的连接。
【单选题】The magician said to the audience: “Ladies and gentlemen, before your very I will now make this
A.
131. The magician said to the audience: “Ladies and gentlemen, before your very I will now make this rabbit disappear.” A.eye
【单选题】Are your lifeboats fitted with_____?
【单选题】An aneroid barometer is an instrument ___
A.
used to measure the speed of wind
B.
in which the pressure of the air is measured
C.
that tells which direction a storm is coming from
D.
used to measure the height of waves
【多选题】世界卫生组织(WTO)提出,衡量婴幼儿生长发育的科学的标准应该是三把”尺 子”,即( )
【单选题】预紧力为F'的单个紧螺栓连接,受到轴向工作载荷F作用后,螺栓受到的总拉力F 0 ( )F'+F。