Windows Communication Foundation （WCF） application uses a data contract that has several data members. You need the application to throw a Serialization Exception if any of the data members are not present when a serialized instance of the data contract is deserialized. What should you do？（） [" Add the Known Type attribute to the data contract.Set a default value in each of the data member declarations."," Add the Known Type attribute to the data contract.Set the Order property of each data member to unique integer value."," Set the Emit Default Value property of each data member to false."," Set the Is Required property of each data member to true."]
事实婚姻的处理
试述你对拥刘反曹思想倾向的理解。
水泵接合器的安装要求正确的是（）。 ["水泵接合器接口距室外消火栓或消防水池的距离宜为10～40m","墙壁水泵接合器安装高度距地面宜为0.7m","墙壁水泵接合器与墙面上的门、窗、孔、洞的净距离不应小于2.0m，且不应安装在玻璃幕墙下方","地下水泵接合器的安装，应使进水口与井盖底面的距离不大于0.4m，且不应小于井盖的半径","水泵接合器与给水系统之间不应设置除检修阀门以外其他的阀门"]
网络虚拟化的本质是（）和（）。
种群的群特特征？
