单项选择题 When there is no movement of the rams on an electro-hydraulic steering gear, the tilting box of the running pump is （）.

单项选择题 The structural members of the hull extending in a fore and aft direction are called （）.

单项选择题 Increased internal leakage, in addition to poor hydraulic system response,and inadequate lubrication, is the result of （）.