如何向列表框中的项目显示不同的文本

Question

当我按下按钮

时，如何在列表中显示定义而不是文本

public partial class Form1 : Form
{
    public Form1()
    {
        listBox1.SelectionMode = SelectionMode.MultiSimple;
        InitializeComponent();
    }

    private void listBox1_SelectedIndexChanged(object sender, EventArgs e)
    {
        listBox1.Items.Add("Opportunity cost");
        listBox1.Items.Add("consumer surplusSurplus");
        listBox1.Items.Add("inflation");
    }           

    private void button1_Click(object sender, EventArgs e)
    {
        foreach (Object obj in listBox1.SelectedItems)
        {
        }
    }
}