如何使用linq从集合中获取特定的集合？

using System;
using System.Collections.Generic;
using System.Linq;

public class Student
{
    public string Name { get; set; }
    public int Age { get; set; }
}

public class Program
{
    public static void Main()
    {
        List<Student> students = new List<Student>
        {
            new Student { Name = "Alice", Age = 20 },
            new Student { Name = "Bob", Age = 17 },
            new Student { Name = "Charlie", Age = 19 }
        };

        var adults = students.Where(s => s.Age > 18);

        foreach (var student in adults)
        {
            Console.WriteLine($"{student.Name} is {student.Age} years old.");
        }
    }
}

var adults = students.Where(s => s.Age > 20); // 如果集合中没有年龄大于20岁的学生，结果将为空

// 假设students是一个非常大的列表，可以考虑使用AsParallel进行并行查询
var adults = students.AsParallel().Where(s => s.Age > 18);