3 is C i believe, and as for 4 minerals are solid, natural.. that's about all I can say...
Answer is: <span>concentration of fluoride in the water in parts-per-million is 1 ppm.
</span>Parts-per-million (10⁻⁶) is<span> present at one-millionth of a </span>gram per gram of sample solution, f<span>or example mg/kg.
</span>m(fluoride) = 500 g · 1000 mg/g = 500000 mg.
m(water) = d(water) · V(water).
m(water) = 1 kg/L · 500000 L.
m(water) = 500000 kg.
arts-per-million = 500000 mg ÷ 500000 kg = 1 mg/kg = 1 ppm.
I believe it’s A..but I’m not quite sure.
I think it converts electrical energy to sound energy because, say if you're listening to music on your phone but, with the speaker on. The speaker of the phone on the other end changes the electrical energy/ electromagnetic waves back into sound energy. I believe the same goes with headphones
<span>All bulbs/plants and creatures </span>want nitrogen<span> to produce amino hallucinogen, proteid and DNA, although this </span>nitrogen<span> in the air is not in a manner that everybody can use.
For more information, look at the appendage below!</span>