Usually means that something failed and your variable is not what you expect it to be. $connection is probably false .
Since you using prepare, you should make the $cond a named parameter and then do this: in this example the condition is just user_id, but you can have multiple conditions and multiple named parameters, just bind() each one the same way.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.