如何在C#中使用异步技巧来处理IO和CPU混合绑定的任务？

using System;
using System.IO;
using System.Net.Http;
using System.Threading.Tasks;

public class Program
{
    public static async Task Main()
    {
        // 异步读取文件
        await ReadFileAsync("file.txt");

        // 异步发送HTTP请求
        await SendHttpRequestAsync("https://example.com");

        // 异步执行CPU密集型操作
        await RunCpuIntensiveTaskAsync();
    }

    public static async Task ReadFileAsync(string filePath)
    {
        using (var reader = new StreamReader(filePath))
        {
            string content = await reader.ReadToEndAsync();
            Console.WriteLine(content);
        }
    }

    public static async Task SendHttpRequestAsync(string url)
    {
        using (var client = new HttpClient())
        {
            string response = await client.GetStringAsync(url);
            Console.WriteLine(response);
        }
    }

    public static async Task RunCpuIntensiveTaskAsync()
    {
        await Task.Run(() =>
        {
            // 执行CPU密集型操作
            for (int i = 0; i < 1000000000; i++)
            {
                // do something
            }
        });
    }
}