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 What happened：never had (1. 4); turned round (1. 7); flew
back (1. 7); told (1. 8); learnt (1. 10); was searched (1. 11);
was found (l. 12); were able to take off (1. 12)
What was happening：were flying (1. 6); and slowly gaining (1.
6); were waiting (1. 8)
What used to/would happen：used to travel (1. 1); used to live
(1. 2); used to fly (1. 2); would take charge (1. 3)
C (sample answers)
1 In the past (but not now), I habitually flew there from
Europe in the holidays.
2 I am accustomed to travelling by air now (because I have
done it many time).
Key to SD Exercises
1 over 2 off 3 in 4 up⋯ up
5 after 6 off 7 down 8 off
Key to Multiple choice questions
1 b 2 d 3 c 4 c
5 a 6 d 7 b 8 a
9 d 10 a 11 a 12 c
Key to Sentence structure
Only on one occasion have I ever felt frightened.

祝同学学习进步~