Lesson 71 A famous clock

When you visit London, one of the first things you will see is Big Ben, the famous clock which can be heard all over the world on the B.B.C. If the Houses of Parliament had not been burned down in 1834, the great clock would never have been erected. Big Ben takes its name from Sir Benjamin Hall who was responsible for the making of the clock when the new Houses of Parliament were being built. It is not only of immense size, but is extremely accurate as well. Officials from Greenwich Observatory have the clock checked twice a day. On the B.B.C. you can hear the clock when it is actually striking because microphones are connected to the clock tower. Big Ben has rarely gone wrong. Once, however, it failed to give the correct time. A painter who had been working on the tower hung a pot of paint on one of the hands and slowed it down!

当你游览伦敦时，首先看到的东西之一就是“大本”钟，即那座从英国广播公司的广播中全世界都可以听到它的声音的著名大钟。如果不是国会大厦在1834年被焚毁的话，这座大钟永远也不会建造。“大本”钟得名于本杰明.霍尔爵士，因为当建造新的国会大厦时，他负责建造大钟。此钟不仅外型巨大，而且走时也非常准确。格林尼治天文台的官员们每天两次派人矫正此钟。当大钟打点的时候，你可以从英国广播公司的广播中听到，因为钟塔上接了麦克风。“大本”钟很多出差错。然而有一次，它却把时间报错。在钟塔上干活的一位油漆工把一只油漆桶挂在了一根指针上，把钟弄慢了！

Grammar

1.复习if第三类条件句。

2. 定语从句总结

If第三类条件句是指与过去相反的条件句，其构成结构为：if+过去完成时，主句用过去将来完成时。

Exercise

1. If you hadn’t helped me with my work, I __________ it on time.

A. wouldn’t finish   B. wouldn’t have finished

C. hadn’t finished   D. didn’t finish

2. I tried to explain to him that I was not responsible __________ this matter.

A. for   B. to   C. in   D. with

解析：1. 考查if非真实条件句第三类，从句为过去完成时，主句使用would have done结构，因此此处只能选择B。答案：B。

2.考查固定搭配介词词组，be responsible for“对…负责”。答案：A。