18.The Leaning Tower of Pisa
The tower of Pisa has never been upright. Its leaning can date back to the time not long after it was built in 1173. First, the tower tilted towards the north. Then during the prolonged process of construction till 1370, the tower had always been leaning to the south.
Throughout the monuments history, many efforts have been made to halt the lean. These efforts have so far helped prevented the tower from topping over. But since 1911, the offset at the top of the tower has increased at a fairly consistent rate. Shortly after 1989, for the sake of safety, the tower at Pisa was closed to visitors.
In 1990, a special commission was organized to find new ways to save the tower. At first the commission worked mainly on the outside of the tower, but in the next few months, more radical techniques will be tried to stop the towers lean. The ultimate goal is not to straighten the tower but to ease its top back a little. With luck, the landmark can stand into the next century.
2014秋闽教版英语三上《Unit 2 Greetings》ppt课件3
2013闽教版四上《Unit 2 On Duty》ppt课件1
闽教版[2013版]三上《Unit 3 Numbers》ppt课件2
闽教版[2013版]三上《Unit 7 School Things》ppt课件1
2013闽教版六上《Unit 5 Daily Schedule》ppt课件2
2013闽教版六上《Unit 5 Daily Schedule》ppt课件1
2014秋闽教版英语三上《Unit 1 Hello》ppt课件1
2013闽教版六上《Unit 6 Food and Health》ppt课件1
2013闽教版六上《Unit 3 Getting Ready for a Trip》ppt课件1
2013闽教版五上《Unit 2 Back to School》ppt课件
闽教版[2013版]三上《Unit 2 Greetings》ppt课件1
2013闽教版四上《Unit 8 Christmas》ppt课件
2013闽教版四上《Unit 4 Time》ppt课件
2016秋闽教版英语四上Unit 2《Our School》(Part A)ppt课件2
2014秋闽教版英语三上《Unit 2 Greetings》ppt课件2
闽教版[2013版]三上《Unit 5 My Families》ppt课件
2013闽教版四上《Unit 3 Numbers》ppt课件2
2013闽教版四上《Unit 3 Numbers》ppt课件1
闽教版[2013版]三上《Unit 6 Colors》ppt课件
2013闽教版六上《Unit 8 Thanksgiving(2)》ppt课件
2013闽教版六上《Unit 6 Food and Health》ppt课件
2013闽教版六上《Unit 4 On Holidays》ppt课件1
2013闽教版五上《unit 1 Getting Ready for school》ppt课件
2013闽教版四上《Unit 5 Meals》ppt课件
2016秋闽教版英语四上Unit 1《Our Classroom》(Part A)ppt课件1
闽教版[2013版]三上《Unit 3 Numbers》ppt课件1
2013闽教版四上《Unit 5 Meals》ppt课件1
2013闽教版四上《Unit 7 The Seasons》ppt课件
2013闽教版四上《Unit 9 Spring Festival》ppt课件
2014秋闽教版英语三上《Unit 1 Hello》ppt课件2
| 不限 |
| 英语教案 |
| 英语课件 |
| 英语试题 |
| 不限 |
| 不限 |
| 上册 |
| 下册 |
| 不限 |