单项选择题
What is the result？（）
A.Canada B.null Canada C.Canada null D.Canada Canada E.Compilation fails due to an error on line 26. F.Compilation fails due to an error on line 29.
单项选择题 Which is true？（）
单项选择题 What is the result？（）
单项选择题 What can directly access and change the value of the variable name？（）
