用键盘打开菜单项，必须按住（），再按菜单项括号中的字母即可。 ["Ctrl","Alt","Shift","Ta"]
The purpose of inert gas systems aboard tankers is to（）. ["allow sufficient oxygen in the tank to sustain life","prevent outside air from entering the tank","provide more discharge pressure","comply with pollution regulatio"]
Which of the listed fire extinguishers cannot be easily recharged aboard ship?（） ["Soda acid","Carbon dioxide","Dry chemical","Cartridge-operated Foam"]
已知变压器的变比K＝5，原绕组匝数N1＝2200匝，副绕组匝数N2＝（）匝。 ["11000","1100","440","220"]
用剪贴板复制文件，一般适用于（）情况。 ["距离短，复制一次","距离长，复制一次","距离短，复制多次","距离长，复制多次"]
德国在自然地理上可分哪几部分？各有什么特点？
