This is another standard excerpt that is typically used in orchestral and college placement auditions. This excerpt is from the 1st movement starting at rehearsal 3.
There are a few tricks that I use to help phrase the passages and make distinctions between sections. The first is trying to make sure I’m showing the keys to the listener. While the key signature stays the same throughout this excerpt, there are clear tonal centers. Below I have notated the scale degrees I use to help clearly cadence in a new key.
The next thing I try to show the audience is that there is a 3-note motif that always starts on the tonic and is preceded by an active note (dominant or leading tone). I try to put an ever so slight crescendo on the active note and a small air accent on the tonic. This allows for a smooth slur while still placing emphasis. I have boxed off the 3-note motif below and labeled the notes.
The last thing to consider is the articulations used throughout the piece in unison passages. Below are three different articulations used by instruments being played at the same time. I would experiment with these articulations to see what they each offer.