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
C
1 must not 2 need not
D
1 had to go 2 should have gone
3 should begin
Key to SD Exercises
A
1 queue 2 single
B (sample sentences)
1 It was so funny that I still laugh whenever I think about
it!
2 It's funny (that) he hasn't replied to your letter.
Key to Multiple choice questions
1 a 2 a 3 d 4 a
5 d 6 d 7 a 8 d
9 b 10 d 11 d 12 b

祝同学学习进步~