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CSharp · Console

/Program.cs

using System;
using System.Collections.Generic;

public class Program
{	
	public static void Main()
	{
		List<string> Titles= new List<string>(new string[] { "title1", "title2", "title3" });
		List<Book> Books = new List<Book>{new Book{Title = Titles[0], Author = string.Empty}, new Book{Title = Titles[1], Author = string.Empty}, new Book{Title = Titles[2], Author = string.Empty}};
		// ^ заменить предыдущую строку ^ //
		Console.WriteLine(Books[0].Title);
	}
}

public class Book
{
	public string Title { get; set; }
	public string Author { get; set; }
}