[单选]

You are developing a new version of an existing message contract named CustomerDetailsVersion1. The new version of the message contract must add a Department field of type String to the SOAP header.You create a new class named CustomerDetailsVersion2 that inherits from CustomerDetailsVersion1. You need to ensure that all client applications can consume the service.
Which code segment should you use?（）

《离骚》 关于净现金流量，以下说法正确的有（）。 计算期内每年的净现金流量是计算项目投资决策评价指标的重要依据。 计算期内每年的净现金流量是项目投资决策的重要评价指标。 无论是在经营期内还是在建设期内都存在净现金流量。 只有在经营期内才有净现金流量而在建设期内没有净现金流量。 Your company has a single active directory forest that has an active directory domain named na.contoso.com. a member server named server2 runs the DNS server role. The server2 DNS service hosts multiple secondary zones including na.contoso.com. you need to reconfigure server2 as a caching-only DNS server. What should you do?（） Uninstall and reinstall the DNS service on server2.。 Change all the DNS zones on server2 to stub zones.。 Disable and then enable the DNS service on server2.。 Delete the na.contoso.com DNS zone domain from server2. Restart the DNS service on server2.。 人的本质属性包括（） 自然属性。 思想属性。 社会属性。 道德属性。 钢纤维混凝土破坏形式是（）。 A.纤维被拉断 。 B.纤维从混凝土拔出 。 C.混凝土被拉裂 。 D.纤维被腐蚀。

You are developing a new version of an existing message contract named CustomerDetailsVersion1. The new version of the message contract must add a Department field of type String to the SOAP header.You create a new class named CustomerDetailsVersion2 that inherits from CustomerDetailsVersion1. You need to ensure that all client applications can consume the service.
Which code segment should you use?（）