3.Perhaps the postcode was wrong, and that's why the letter never arrived.

可能邮政编码错了，那就是信一直未收到的原因。 that's why ..."那就是......的原因"，why引导表语从句。 (2017·北京高考书面表达)那就是我认为长江之旅是较好选择的原因。

That's_why I think the trip along the Yangtze River will be a better choice. 4.I was getting more and more annoyed and of course, the more upset I got, the less I was able to concentrate.

我变得越来越烦躁，自然越烦躁越不能集中精力。 the＋比较级 ..., the＋比较级 ..."越......，就越......"。 他们担心你的越少，你越获得更多的独立。

The_less they worry about you, the_more independence you'll gain. 　　

　　二、课堂重点深化

　　1．concentrate vi.集中(思想、注意力等)

　　　[自主体验]

　　单句语法填空

　　①We must concentrate our energy on treating (treat) addiction first.

　　②What's more, I find out that I still have some bad learning habits as well. I can only concentrate on reading for a short time, and I will conquer the problem by spending more efforts on concentration (concentrate) practice.

　　③He made a concentrated (concentrate) effort to finish the work on time.

　　一句多译

　　他将注意力全部集中在技术问题上。

　　④He_concentrated_his_attention_on_the_question_of_technology. (concentrate)

　　⑤He_fixed/focused_his_attention_on_the_question_of_technology. (fix/focus)

　　⑥He_put_his_heart_into_the_question_of_technology.(put one's heart into)

　　　[系统归纳]

　　(1)concentrate on (doing) sth.　　聚精会神于(做)某事

　　concentrate one's attention/energy ... on/upon (doing) ...

　　 集中某人的注意力/精力......于(做)......

　　(2)concentration n. 专心，集中

　　(3)concentrated adj. 集中的，全神贯注的

　[重点强化]