1.A

2.D

3.D

4.C

5.A

6.B

7.C

8.A

9.B

10.A

EX2

1 IS-> was

2 to buy-> of buying

3 because-> although

4 was seeing-> saw

5 although-> because

Ex3

1.The Buffalo- fighting took place in Do Son Saturday because there were so many people

2. We won't hold the festival if It cost too much. 

3. When the prince saw the Sleeping Beauty, he kissed her on the forehead

 4.While the hare was sleeping, The toroise ran.

5. Although the girl worked hard, her stepmother wasn't happy.

EX4

1. A          2. B            3. B          4. D             5. A                6. A

1.A

2.B

3.D

4.A

5.A

6.B

7.D

8.A

9.c

10.D