动词之前或动作已经持续了一段时间，相当于一个状语从句，可替换为：After he had worked there for 30 years，Haydn moved to London，where he was very successful.。

[题组训练]

(1)句型转换

After they had put up the tent，they started to cook the supper.

，they started to cook the supper.

(2)Dina， for months to find a job as a waitress，

finally took a position at a local advertising agency.

A．struggling B．struggled C．having struggled D．to struggle

5．By the time he was 14，Mozart had composed many pieces for the harpsichord，piano and violin，as well as for orchestras.莫扎特到14岁的时候，不仅已经谱写了很多管弦乐曲，还谱写了很多拨弦键琴曲、钢琴曲和小提琴曲。

[归纳拓展]

(1)句中"By the time"用作连词词组，引导一个时间状语从句，意为"在......的时候"，并且主句常用完成时态。

(2)by后接表示过去的时间状语时，多与过去完成时连用；接表示现在的时间状语时，多与现在完成时连用；接表示将来的时间状语时，多与一般将来时或将来完成时连用。

[题组训练]

(1)They their work by the end of last week.

　到上周末他们已经完成了工作。

(2)Maybe she by now.或许现在她已经回来了。

(3)By the time Jack returned home from England，his son from college.

A．graduated B．has graduated C．had been graduating D．had graduated

6．Haydn met Mozart in 1781 and was very impressed with him.海顿于1781年与莫扎特相遇，并对他留下了深刻的印象。

[归纳拓展]

be impressed with/by留下深刻印象 impress sb.with sth.......给某人留下深刻的印象

leave/makes a (an)．..impression on sb.给某人留下......印象

(1)句型转换

Our teacher the importance of industry and economy us.

(2)The speech by the mayor of Shanghai before the final voting for EXPO 2010 was strongly impressed my memory.

A．to B．over C．by D．on

7．However，it was Haydn who encouraged Beethoven to move to Vienna.然而，是海顿鼓励贝多芬去维也纳的。

[归纳拓展]

It was...who..."是强调句，本句强调主语。正常的语序为"Haydn encouraged Beethoven to move to Vienna."。

强调句型的基本结构是：