What are some of the difficulties with measuring the volume of a gas? Select all that apply. (A) it could be soluble in liquid
(B) it can be difficult to contain.
(C) it varies depending on the container it is in
(D) it varies based on its mass

it is ---D because you can't measure gas and it's mass

HOPE THIS HELPS

it's when something is going so fast it makes a loud noise, breaking the sound barrier, for example: a jet makes a loud noise, not only cause of the jet but because they reached a point where they went so fast that you can year the noise from various parts, kinda like a police car, lets say the car was going   so fast that you hear the siren of the cop car right next to you, but the car is probably a mile a way, it's cos the siren was next to you a few seconds if you understand me