植物必需营养元素的有效性受土壤酸碱度的影响，其中磷的有效性最大的pH值范围是（） ["A、4-9 ","B、6-7 ","C、4-6 ","D、7-9"]
Router NetworkTut is configured as shown below： Given the above configuration， which statement is true？（） ["This device is configured as a PPPoE client","This device is configured as a PPPoA client","This device is configured as RFC 1483\/2684bridge","This device is configured an an aggregation router"]
发动机大修主要取决于（）。 ["曲轴的磨损程度","气门磨损程度","轴瓦磨损程度","活塞与气缸壁的间隙"]
You are developing a Windows Communication Foundation (WCF) service. One of the parameters used with the service operations is a security token. The security token is not sensitive. The monitoring software tracks security tokens and can read tokens in clear text only.The company security policy requires that you validate all clear text data passed over the corporate network.You need to ensure that the service verifies that the security token is not changed during transit. What should you do?（） [" For all the security-sensitive members, set the ProtectionLevel parameter of the MessageBodyMember or MessageHeader attribute to EncryptAndSign."," Implement IEndpointldentityProvider in the message contract class."," Implement ISecureConversationSession in the message contract class."," For all the security-sensitive members, set the ProtectionLevel parameter of the MessageBodyMember or MessageHeader attribute to Sign."]
SQL中用来更新数据的命令有（） ["Insert","Delete","Update","Select"]
简述接生羔技术。
