Great photographs. Capturing fireworks in low lighting situations can be quite a challenging task. You’ve done a great job with both of these photographs. You’ve shown that you understood what the assignment asked of you. From a technical standpoint you’ve completed the assignment and shown your understanding of aperture and shutter control.
However, I want you to keep a closer eye on the 4 walls of your photograph. In both pictures you’ve managed to line up the main attraction (main subject) in the proper position in the frame. It looks like thought has gone into the composition of the main subject. However, it seems to me that your eye might be wandering away from the 4 walls of the photograph. In the fireworks photograph you’ve cut off some of the fireworks streams. Which is arguably fine, but it might have been more dramatic if the entire firework was located within the frame.
In the photograph of the plant, the depth of field is great. You’ve managed to use DOF to help your main subject “pop” out. However, notice how your plants leaf (at the top) is cut off by the upper wall of the photograph? I think it would have looked nicer to include the whole leave or find a subtler way to make that amputation if it was absolutely necessary.
Both photographs show your skill from both an artistic and technical standpoint. The main point I’m trying to make is that they smallest details of composition are prohibiting your photographs from being spectacular. With photography, like with many art forms “the devil is in the details”. In your next assignment I want to see you pay extra close attention to the 4 walls of your photograph.