ex-1.
1. c 2. d 3. e 4. a 5. b
ex-2
1. a 2. c 3. a 4. c 5. a
ex-3
1. e 2. c 3. d 4. a 5. b
ex-4
1. a
2 c3 a
4 c
5 a
6 b
7 a
8 c
9 a
10 work
