同学你好，该知识点来自沪江网校《新概念英语1、2、3、4册连读【4月班】》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~
答案如下：

Key to KS Exercises
A
detectives were waiting (1.1); They were expecting (1.2);
detectives were waiting (1.5); others were waiting (1.6); two
detectives were keeping guard (11.7-8)
B
1 When the plane arrived, some of the detectives were waiting
inside the main building while others were waiting on the airfield.
2 When two of the detectives opened the parcel, two others
were keeping guard at the door.
C (sample answers)
1 I was getting into my bath when you telephoned me.
2 I was reading Hamlet when you saw me in the library this
morning.
3 I was saying that you must see the new film when you
interrupted me.
D
1 was leaving ⋯arrived
2 worked/was working ⋯ was sitting/sat
3 was walking ⋯ met
4 was reading ⋯ heard
5 was preparing ⋯ set/was setting
6 dropped ⋯ spoke
Key to SD Exercises
1 He gave all his books away.
2 She woke the children up early this morning.
4 They cut the king's head off.
5 Put your hat and coat on.
7 Help me to lift this table up.
8 Take your shoes off and put your slippers on.
11 They have pulled the old building down.
12 Make your mind up.
14 She threw all those old newspapers away.
Key to Multiple choice questions
1 b 2 c 3 c 4 d
5 a 6 c 7 d 8 a
9 c 10 b 11 a 12 b
Key to Sentence structure
Two men took the parcel off the plane and carried it into the
Customs House.

祝同学学习进步~