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改进这个问题
我很难用java来做这个map和hashmap，因为我还在学习它。所以我们有这个活动，我已经完成了一半，我的问题是我不知道如何删除java中条目的Map。有人知道怎么做吗。谢谢。

import java.util.Scanner;
import java.util.Map;
import java.util.HashMap;

public class StudentList {

public static void main(String[] args) {
Scanner input = new Scanner (System.in);
Map<String,String> Student = new HashMap<>();

for (int i=1;i<=3;i++){
    System.out.print("Enter student number " + i + ": ");
    String num = input.nextLine();
    System.out.print("Enter first name " + i + ": ");
    String name = input.nextLine();
    Student.put(num,name);
}
System.out.println("Student List:");
for(Map.Entry List:Student.entrySet())
    System.out.println(List.getKey()+ "  " +List.getValue());
}
}
//This is the output of it.   
Enter student number 1: 0004
Enter first name 1: Mary
Enter student number 2: 0018
Enter first name 2: Nica
Enter student number 3: 0145
Enter first name 3: Mae
Student List:
0018  Nica   // I also have a problem here, idk why Nica is 1st on the list and not Mary.
0004  Mary
0145  Marc

//This is the part of the instruction in our activity.
The output shall:
-Ask three (3) of your classmates to enter their student number (key) and first name (value).
-Display the keys and values of the map.
-Delete the mapping of the third entry
-Enter your student number and first name. This would be the new third entry.        
-Display the entries in separate lines.