The 'burden of proof' is on the plaintiff, since the defendant is presumed innocent until proven guilty. [=the plaintiff must prove that the defendant is guilty]
The 'tax burden' has been falling increasingly on the middle class. [=middle class people have been paying a greater portion of taxes]
For the rest of his life he 'was burdened' with the knowledge that he had done nothing to help them.
(..) all the more. Okay. How can I be a father when I'm heading the other direction? It's not fair to a child. I don't wanna be anybody's burden. Sugar, we all end up in diapers. I'm gonna make this work. I want this, and I want it with you. I want you to have (..)2008 The Curious Case of Benjamin Button