简述九江头槽绦虫病的病原。
The test of a towing vessel’s steering gear control system includes each item EXCEPT（）. ["a test from the alternative power supply，if installed","timing the movement of the rudder from hard over to hard over","verification that the rudder angle indicator shows the actual position of the rudder(s)","visual inspection of the steering linkage"]
经承运人同意，非溢漏型电池作为托运行李必须如何准备？（） ["电池处于断路状态","从电池中排空液体","绝缘电池的接线柱","安全连接轮椅电池"]
LED显示屏执照发光颜色可分为（）。 ["单色显示屏","双基色显示屏","四基色显示屏","全彩色显示屏"]
含有溢漏型电池的电动轮椅，在操作中无法做到以直立方式装载、放置、固定和卸机，那么应采取哪些措施？（） ["事先征得承运人同意，做好安排","卸下电池","把电池装入坚固的硬质包装中","通知机长轮椅或已包装电池的位置"]
煤的岩相结构如何，有何应用价值？
