重点讲解：
1. first of all
第一；首先；
eg. First of all, you should know what profession suits you.
首先，你该知道什么职业适合你。
eg. First of all, let's set the scene.
首先让我们来叙述一下背景。
2. decide to do sth.
决定，拿定主意（做）某事；
eg. He has decided that he doesn't want to embarrass the movement and will therefore step down.
他已拿定主意：他不想令运动陷入困窘的境地，因此决心辞职。
eg. The house needed totally rebuilding, so we decided against buying it.
这所房子需要彻底重建，因此我们决定不买了。