练习材料：
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 hot 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 !
任务配置：L0+L4
知识笔记：
Big Ben 大本钟
the Houses of Parliament 英国国会大厦
parliament /ˈpɑːləmənt/ n. 议会，国会；英国议会，英国国会
erect /ɪˈrɛktɪd/ v.建造，搭建
Sir Benjamin Hall 本杰明.霍尔爵士
immense /ɪˈmɛns/ adj. 极大的，巨大的
extremely /ɪksˈtriːmli/ adv. 非常，极度
accurate /ˈækjərət/ 准确的，精确的
Greenwich Observatory 格林威治天文台
strike /ˈstraɪk/ v. （时钟）敲响，打点
rarely /'reəli/ adv. 罕有，很少，极少
a pot of paint 一罐油漆
练习感悟：
总体不难， observatory是第一次见，读了几次才读熟。
今天也坚持了，明天加油！
