单项选择题
What is the result？（）
A.A,B,C B.B,C,A C.Compilation fails. D.The code runs with no output E.An exception is thrown at runtime.
单项选择题 What inserted at line 39， will sort the keys in the props HashMap？（）
单项选择题 What is the result？（）
单项选择题 Given that the elements of a PriorityQueue are ordered according to natural ordering， and： What is the result？（）
