1. a

2. b

3. a

4. b

1. B

2. C

3. A

1 - c

2 - b

3 - a

1. useful - careful

2. useless - interested

1. devices - communicate

2. donate - volunteer

1 - d

2 - c

3 - b

4 - a

1. is used

2. are planted

3. will pass

4. will

5. are going to

6. is going to rain

1 - c

2 - a

3 - b

1. A

2. C

3. B

1. difficulties

2. love

3. sad