重点讲解：
1. first of all
第一；首先；
eg. First of all she just smiled, then she started to laugh.
最初她只是微笑，后来才放声大笑。
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. Well, first of all we can't possibly spare the time.
你看，最主要的是我们实在抽不出时间。
2. let's see
口语常用，（表示试图记起某事或找到某物）让我想一想，让我看看；
eg. Let's see, they're six — no, make that five hours ahead of us.
让我想一想，他们比我们早 6 个——不，就算是早 5 个小时完成。
eg. Oh, let's see. It'll be about 3:30 before we have anybody free.
哦，让 我 想想。大概要到3:30我们才有空。
eg. Let's see, our flight number is CX360 monitor says our flight is on time.
让我看看，我们的航班号是CX360，显示屏上显示我们的航班准时到了。
