在Windows操作系统中，当用户双击“IMG_20160122_103.jpg”文件名时，系统会自动通过建立的（）来决定使用什么程序打开该图像文件。 ["文件","文件关联","文件目录","临时文件"]
bill has an author names field named all editors that calculates a list of possible editors of the doc based on values users has entered into another field. The list only contains users’ first and last names, and only should be displayed to users who can edit doc.Which of the following hide-when formulas should bill use to control the display of the field?（） [" @isnotmember(alleditors,@username) "," @isnotmember(@name([cn]);@username) "," @isnotmember(alleditors;@name([cn ];@username)) "," if(@isnotmember(alleditors;@name([cn];@username);@true;@false))"]
基尔霍夫定律包括基尔霍夫电流定律（KCL）和基尔霍夫（）定律（KVL）。 ["电压","电阻","电容","电子"]
GK型三通阀701型试验台紧急制动试验中，制动管减压（）以前必须发生紧急制动。 ["20kPa","25kPa","40kPa","140kPa"]
RAID DP最多允许多少块硬盘同时损坏，而且不影响数据（） ["1","2","3","4"]
请任意写出几种机组中使用到的倍福PLC模块,并写出其功能.
