most likely water
Soft drinks have a pH under 7.
Milk and water
Yes
Alka-Seltzer has a pH of around 9, so the pH itself won't kill you. Whatever is in it making it have that pH might.
Diet coke
Water,skim milk and natural juice.
Sparkling natural mineral water.
Orange because it has vitamin C
Depending on kind and brand between 2.5 and 4.5 when carbonated and juicy
You can test it with a strip of the stuff you use to test pH levels
Water, without it you will be dead in a matter of days.
none. water only.