If all the oxygen atoms in the human body were oxygen-18. Would the human have gained or lost weight? How much?

This has nothing to do with school. i wrote a poem to my crush, who i'm asking out soon. tell me if it's cheesy, or cute. "roses are red, violets are blue no love story sounds right if it doesn't include you. dance with me all night, gaze into my eyes i'll hand you my heart, as well as my pride. when i hear your name, my heart goes insane. your all that i want, all that i need promise me you'll stay with me. here it is the final line, jasmine hill will you be mine? " i'm also going to buy her flowers, teddy bear and some food lol. written by me, bre (:

How is it possible for someone to put an ear to a wall and hear someone in the next room?     a.sound waves can travel though solids.    b.the waves travel from room to room via air.    c.there must be some air in the wall so the sound can travel through it.    d.sound waves change to electromagnetic waves and then back again.

If a refrigerator is a heat pump that follows the first law of thermodynamics, how much heat was removed from food inside of the refrigerator if it released 300j of energy to the room?unit: