同学你好，该知识点来自沪江网校《新概念英语2、3、4册连读【双11专享班】》的课程，想要更系统的学习，欢迎进入课程学习。不仅可以和更多的同学一起学习，而且还有老师、助教随时的学习指导和知识点解答哦。

同学你好~
Key to KS Exercises
A the most extraordinary building of the nineteenth century
(1. 1); one of the biggest buildings of all time (11. 4-5), The
most wonderful piece of machinery on show (11. 8-9); travelling
was not as easy as it is today (1. 9); one of the most famous
buildings in the world (1. 13)
Key to SD Exercises
1 on duty
2 On second thoughts
3 on purpose
4 on foot
5 on the whole
6 on any account
7 On the average
Key to Multiple choice questions
1 c 2 b 3 d 4 a
5 d 6 c 7 a 8 d
9 c 10 c 11 d 12 b
Key to Sentence structure
The Crystal Palace was different from all other buildings in
the world, for it was made of iron and glass.

祝同学学习进步~