【单选题】Which system(s) in the hydraulic systems of crane always hold(s) single side of load?
B.
hoisting system and luffing system
C.
hoisting system and slew and slewing system
【单选题】For a balanced three-phase △ -connected load, the average power absorbed by the load is P . Change the △ -connected load to Y-connected load, the power will :
【单选题】The slender column is under axial compressive load P, the critical load 【图片】is independent of ( ).
A.
the material of the column
B.
the length of the column
C.
the magnitude of the P
D.
the shape and dimension of the cross section of the column
【单选题】The vessel’s load line certificate is always issued by ____.
A.
The register of shipping
D.
maritime safety administration
【单选题】One should always be careful with _ (load) guns.
【单选题】The vessel’s load line certificate is always issued by ____.
A.
the register of shipping
D.
maritime safety administration
【单选题】The load on the crosshead pin is always ______, so it is the ______ half of the bearing which is subject to wear.
【单选题】下列关于胫前动脉和足背动脉的描述,错误的是
D.
其体表投影为:胫骨粗隆与腓骨小头连线中点至足背内、外踝连线的中点为胫前动脉;自足背内、外踝连线中点至第1、2跖趾关节间的连线为足背动脉
E.
在内、外踝连线中点向深部压迫足背动脉,可止血
【单选题】The vessel’s Load Line Certificate is always issued by ().
A.
The Register of Shipping
D.
Maritime Safety Administration