Question

how do you seal your n95 respirator? press firmly all over, quick deep breath in and out with hands firmly on the mask, nothing, its fine because its fitted, shake your head back and forth fast

Explanation:

To seal an N95 respirator properly, one should press firmly all over to ensure a tight - fitting seal. Quick deep breaths are for fit - checking, not for sealing. Shaking the head is not a proper sealing method. Assuming it's already fitted is not correct as proper sealing is necessary for protection.

Answer:

Press firmly all over