TTG ATG ACG
Swap every Adenine (A) for a Thymine (T), every Uracil (U) for an Adenine, every Cytosine (C) for a Guanine (G), and every Guanine (G) for a Cytosine (C).
Other reasons are
Not finishing the antibiotics.
Or
Taking antibiotics too often
My Answer: The death rate begins to fall, but birth rates remain high for a time.
Why?: Many of our countries are in Stage 2, that is why the government is concerned about our overpopulation.
Hope I helped! :D