【判断题】颊肌纤维向前交叉参与口轮匝肌的组成,它 的主要作用是牵拉口角向后,使颊部更接近上下牙列,有助于咀嚼和吮吸。
【单选题】No damage of any kind ______ aids to navigation or navigation facilities.
【单选题】According to the principle of operation, navigation system can be divided into instrument navigation systems, , inertial navigation systems, astronomical navigation systems and integrated navigation ...
A.
Independent navigation systems
B.
Dependent navigation systems
C.
Short range navigation systems
D.
radio navigation systems
【单选题】Navigation details including soundings, nature of the bottom, navigational marks etc. are shown in ____
【单选题】The GPS navigation system is _____.
A.
a global navigation system
B.
a short-distance navigation system
C.
a middle-distance navigation system
D.
a long-distance navigation system