芯棒返回辊道为何倾斜?
参考答案:
使芯棒矫直,冷却均匀,防止弯曲。
I know a little bit about Italy as my wife and I _____ there several years ago. [ ]
A. are going
B. had been
C. went
D. have been
When engaged on international voyages, ships of 1600 tons gross tonnage and upwards shall be fitted with a().
A.radio direction-finding apparatus
B.DSC
C.NAVTEX
D.EPIRB