If you want to be sure that every object is closed, I would use this method:
using (SqlConnection objConnection = new SqlConnection(@"Integrated Security=SSPI;Persist Security Info=True;Initial Catalog=Northwind;Data Source=.;Max Pool Size=1"))
using (SqlCommand objCommand = new SqlCommand("Select * from customers", objConnection))
using (SqlDataReader reader = objCommand.ExecuteReader(System.Data.CommandBehavior.CloseConnection))
The first ever language I started with was QuickBasic and soon I switched to Borland C++ 3.0. Then I attended computer science school where I learned Cobol, Access and ASP. Now I use VB6, VB.NET, C#, ASP.NET, PHP languages with MSSQL and MySQL databases.