仍然是有关xml的
 
You load an XmlDocument named doc with the following XML.
<bookstore>
<books>
<book genre=”reference”>
<title>Dictionary</title>
</book>
<book genre=”reference”>
<title>World Atlas</title>
</book></books>
</bookstore>

You need to change the value for the genre attribute to NA for all book attributes.
First, you add the following code segment to your class. 

XmlElement root = doc.DocumentElement;
XmlNodelist nodes = root.SelectNodes(“books/book”);
Which additional two code segments can you use to achieve this goal?(Each correct answer presents a complete solution. Choose two.)
A.  foreach(XmlNode node in nodes){node.Attributes[0].Value = “NA”;}
B.  foreach(XmlNode node in nodes){node.Attributes[1].Value = “NA”;}
C.  foreach(XmlNode node in nodes){XmlNode genre = node.SelectSingleNode(“/genre”); genre.Value = “NA”;}
D.  foreach(XmlNode node in nodes){XmlNode genre = node.SelectSingleNode(“@genre”); genre.Value = “NA”;}
E.   foreach(XmlNode node in nodes){XmlNode genre = node.SelectSingleNode(“genre”); genre.Value = “NA”;}