RADSS型母差保护屏上有哪些信号？
In a diesel engine, when the fuel is injected into the cylinder,（） the piston is just coming upward from the bottom dead center。 the piston has moved about one-fifth of the way up。 the piston has moved most of the way up and almost reached the TDC。 the piston has just past the TDC。
在Internet服务中，一般不使用公用名和公共口令的是（）。 FTP。 BBS。 电子邮件。 某些ISP。
RADSS母线差动保护如何加用和停用？
One of the differences between a two-stroke engine and a four-stroke engine is,（） a two-stroke engine can’t work without cylinders。 a two-stroke engine can’t work without pistons。 a two-stroke engine can’t work without crankshafts。 a two-stroke engine can’t work without a blower。
You are on a vessel that cannot comply with the spacing requirement for masthead lights.What is required in this situation（）.
