[单选] The Navigation Rules state that a vessel shall be operated at a safe speed at all times so that she can be stopped within（）.
A . The distance of visibility B . 1/2 the distance of visibility C . A distance appropriate to the existing circumstances and conditions D . The distance that it would require for the propeller to go from full ahead to full aster
工商部门可以根据（）等途径判断是否应当采取有效措施对企业实施退出督查。 A.相关部门通报。 B.系统工作提示。 C.年检。 D.举报人举报。 E.检查。
简述我国500kV变电站微机控制系统的发展历史。
通常数码相机有三种可供选择的图片模式是（）。 AVI。 JPEG。 TIFF。 RAW。
（） is/are the legal survey institution(s) that stated by PRC. Ship Survey Bureau。 CCS。 Maritime Safety Administration。 all of the above。
镜头的种类可以包括（）。 标准镜头。 广角镜头。 远摄镜头。 变焦镜头及特殊用途镜头。
The Navigation Rules state that a vessel shall be operated at a safe speed at all times so that she can be stopped within（）.
