问答题

【说明】StringEditor类的功能是：已知一个字符串，返回将字符串中的非字母字符都删除后的字符串。
public (1)
public static String removeNonLetters( (2) )
StringBuffer aBuffer= (3) ;
char aCharacter;
for(int i=0; i＜original.length();i++)
aCharacter= (4) ;
if(Character.isLetter(aCharacter))
aBuffer.append( (5) );

return new String(aBuffer);

public class StringEditorTester
public static void main(String args[])
String original="Hi!, My Name is Mark, 234I think you are my classmate!!";
System.out.println(StringEditor.removeNonLetters(original));