三焦的募穴是:
A.中极
B.石门
C.京门
D.章门
E.天枢
参考答案:B
_______ necessary for us _______ English well.
A.It’s; to learn B.It’s; learn C.That’s; learn
电缆桥架内敷设的电缆,在拐弯处电缆的弯曲半径应以最大截面电缆允许弯曲半径为准。( )