In motor-ships, （）, after passing through main and motion bearings and oil cooled pistons, etcis either retained in the bedplate. ["the fuel oil","the lubricating oil","the refrigerating oil","the hydraulic oil"]
《四洲志》是林则徐主持编译的一部世界地理著作。
The fittings used to secure a watertight door are known as（）. ["clamps","clasps","dogs","latche"]
为什么池塘养殖要配备一定的投饲设备？
In motorships，there are two main circuits, （）. ["one salt water, one fresh water","one salt water, one fuel","one fresh water, one fuel","one steam, one fuel"]
卷烟、雪茄烟的产量计划是由哪些部门下达的？
