DNA testing which I think is the largest breakthrough.
Answer:
To Put of a Fire.
Explanation:
incase an emergency happens, it's important to have a fir extingushier so the situation doesn't get worse and you can put out any possible fire's.
An ionic bond is a type of chemical bond formed through an electrostatic attraction between two oppositely charged ions. Ionic bonds are formed between a cation, which is usually a metal, and an anion, which is usually a nonmetal. A covalent bond involves a pair of electrons being shared between atoms.
0.0015 kilometers is for sure the answer!