重点讲解：
1. used to do sth.
过去常常；过去曾做某事；
eg. We used to compete on just cost.
我们曾经仅仅在成本上竞争~iJ,yUe,(Vc5T9KG。
eg. Marjorie Baer used to joke about her retirement plans.
玛乔丽贝尔曾经拿她的退休计划开玩笑|TV^cYTbi8.V8VlS。
2. first of all
第一；首先；
eg. My aim was first of all to determine what I should do next.
我的目标首先是要确定自己下一步该做什么J6dU,8FoD*WC1]sbm4。
eg. First of all, to try to keep calm at the interview.
首先，面试时要保持镇静2apr@KecCj|Y4jXp3。
3. keep sb. from doing sth.
阻止（或防止、阻碍）…做某事；
eg. Embarrassment has kept me from doing all sorts of things.
我总是害怕受窘，什么事都不敢去做Wed+EQ~~5N0k|Qs6L%1P。
eg. He kept her from being lonely.
他不让她感到孤独99YJLJU=f1TXC~sN_=g。