cupsful, cutiful, dureful, dutiful, gustful, hurtful, hushful, lungful, lustful, museful, pushful, rustful, ruthful, tuneful

The pitch can be changed by tightening or loosening the lips (embouchure), depressing a valve or valves and by moving tuning slides.

The pitch can also be affected by temperature and by the density of the gas being blown through it. Try playing a trumpet with a lungful of helium.

You "clear" the mask by blowing into it before "sealing" the mask by covering the inlet valve and breathing in. If there is chemical agent in the area when you don the mask, breathing in before clearing it will give you a lungful of deadly agent.

They help by allowing the animal to breath.

Dolphins are regular air breathing mammals in the same way as whales, elephants, dogs, cats, apes, etc.

A dolphin will take a deep breath, hold its breath while it swims, and then exchange trhe "used" air in its lungs for a completely new oxygenated lungful of air.

According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 1 words with the pattern -U-GF--. That is, seven letter words with 2nd letter U and 4th letter G and 5th letter F. In alphabetical order, they are:

lungful