初中英语牛津八年级下01

[11:04.58]work eventually began on the bell chamber at the top.
[11:11.53]It was officially opened after nearly 200 years of construction.
[11:19.78]The tower has eight floors.
[11:24.46]It is 54.5 metres tall with 294 steps up to the bell chamber.
[11:36.53]From the top,there is a very beautiful view.
[11:43.09]Italian scientist,Galileo,once did his famous experiments
[11:50.82]about gravityand falling objects from the top of the tower.
[11:57.87]Why does the tower lean?
[12:02.55]In fact,it was already leaning while they were building it.
[12:09.31]As soon as three floors had been built,by 1178,
[12:18.46]it began to lean as the ground beneath it sank.
[12:24.83]The builders tried to make the tower straight again as they added more floors,
[12:34.18]but the lean only got worse as the tower grew.
[12:41.05]It continued to lean by about 1 millimetre every year until finally,
[12:51.08]on 7 January 1990,it was closed to the public.
[12:58.92]For ten years,the rescue of the tower was a serious problem.
[13:06.57]The top was leaning over by 5 metres to the south
[13:13.65]and if its movement was not stopped,
[13:18.69]the tower would one day fall over.
[13:23.74]Measurements taken in 1911
[13:28.99]estimated that the tower would collapse by 2050,if not sooner.
[13:38.55]After 10 years of hard work,it was offivially reopened on 16 June 2001.
[13:50.80]However it was not opened to the public until the end of 2001 and even now,
[14:01.35]the number of visitors is restricted.
[14:05.90]It is now safe for the next 300 years
[14:12.53]because engineers have reduced the lean by 50 centimetres
[14:20.37]to give it the same lean that it had in 1838.