将 List<dynamic> 强制转换为 IEnumerable<Tuple<string，string 时出错>>

问：

我在转换 API 响应类型时遇到问题。该 API 以下面给出的特定格式返回代码List<object>

using System;
using System.Collections.Generic;       
        
public class Program
{
    public static void Main()
    {
        dynamic tupleStringList;
        tupleStringList = new List<dynamic>{Tuple.Create("a","b"),Tuple.Create("c","d")}; // this data will come API which I have no control
        IEnumerable<Tuple<string,string>> test = (IEnumerable<Tuple<string,string>>) tupleStringList;// here we need to cast as another internal function which use it as IEnumerable<Tuple<string,string>>
    }
}

我得到的错误如下

运行时异常（第 9 行）：无法将类型的对象转换为类型。'System.Collections.Generic.List`1[System.Object]''System.Collections.Generic.IEnumerable`1[System.Tuple`2[System.String,System.String]]'

堆栈跟踪：

[System.InvalidCastException: Unable to cast object of type 'System.Collections.Generic.List`1[System.Object]'`` to type 'System.Collections.Generic.IEnumerable`1[System.Tuple`2[System.String,System.String]]'.]  
   at CallSite.Target(Closure,CallSite,Object )  
   at System.Dynamic.UpdateDelegates.UpdateAndExecute1[T0,TRet](CallSite site, T0 arg0)
   at Program.Main() :line 9