Question: Why is the *f* dynamic indication repeated in the last two bars displayed below if a dynamic instruction should last until a different indication occurs?

Also, in the same picture, should the notes between the sforzando indications be played as *ff* (the last dynamic specified before *sf* )?

Thanks for your help!

[![enter image description here](https://i.stack.imgur.com/U0kXr.jpg)](https://i.stack.imgur.com/U0kXr.jpg)

Answer: 
Sforzando only applies to the notes immediately above it, so the notes in between should not be played sforzando.

RE: the repeated forte, this is not necessary. Once forte, the layers must continue to play forte until told otherwise. My guess is that the composer wanted to remind the players to do this every few notes.
The composer wants the staccato notes to be emphasised. But they have a staccato dot over them. They need '>' over as well. There's no room. So he has to put 'f' instead.