[问答题] 简述军用小艇的特点。

Continuous sounding of a fog whistle by a vessel is a signal（）. ["that the vessel is anchored","to request the draw span of a bridge to be opened","of distress","that the vessel is broken down and drifting"] （）是双极型全控电力电子器件。 ["P-MOSFET","TRIAC","GTR","GTO"] 生产中拉伸倍数如何确定？举例说明生产中如何实施？ 生产中影响熟料窑产量的因素有哪些？ 2000年发布实施的《国家行政机关公文处理办法》规定的对外发文的文种有（）种。 简述军用小艇的特点。