求翻译：11、看防护层。为了便于保管，防止零件磕碰，教练车零件出厂之前都有防护层。例如缺套、大小轴瓦、活塞、气门等一般都用石蜡保护，以免其表面损坏。这些重要的配件，表面若无防护层，多为"水货"。是什么意思？

11, look at the protective layer. In order to facilitate the custody, to prevent parts bump before the coach car parts factory has a protective layer. Such as lack of size bearings, pistons, valves, etc. are generally protected with paraffin to avoid surface damage. These important parts, the surfac

11, see protective layer. In order to facilitate guarded in order to prevent parts stumble, coach car parts factory have protective layer before. For example, by default set size bearings, pistons, valves, and other generally used paraffin protection, so as to avoid its surface damage. These importa

11th, looks at the protective layer.For ease of the storage, prevented components clash, before driver training car components exwork all has the protective layer.For example lacks set of, the big and small axle bush, the piston, the tire valve and so on all uses the paraffin wax to protect generall

11, the protective layer. For the purposes of custody to prevent parts bump, before coach car parts factory has a protective layer. Such as short sleeve, bearing, Pistons, valves, and other General wax protection to avoid damage on its surface. Spare parts for these important, if there is no protect