инструкция по пунктам как провести опасный эксперимент
и слова использовать first, then, finally

Ответ:

First you have to prepare a coke and Mentos. Then add vinegar to the cola, And in a bag with mentos suck baking soda. Finally at the end of the bag Soda and mentos in vinegar mixed with cola and get a fountain of cola.