根据Document doc=new News();可以判断选项( )语法上是错误的。
A、Document d = doc;
B、Document d = (News)doc;
C、News d = doc;
D、News d = (News)doc;
发布时间:2025-03-23 04:32:47
A、Document d = doc;
B、Document d = (News)doc;
C、News d = doc;
D、News d = (News)doc;