【简答题】If something is a __________, it is the most important thing you have to do or deal with, or must be done or dealt with before everything else you have to do.
【判断题】It was an easy situation that you can solve because you need to do one thing in order to do a second thing, but you cannot do the second thing until you have done the first.
【判断题】Before you start your application, the first thing you have to do is to make a careful plan about how to find the best schools that suit your needs.()