动画控制器的两种类型。（）
A、多种属性动画控制器
B、单一属性动画控制器
C、复合属性动画控制器
D、不确定
参考答案：B, C
On which vessels is GMDSS required? （）
A.All vessels capable of international voyages
B.Vessels operating outside of the range of VHF coastal radio stations
C.SOLAS Convention ships of 300 gross tonnage or more
D.Coastal vessels of less than 300 gross tons
