III:

1: doesn't speak
2: don't understand
3: doesn't help
4: don't borrow
5: don't play

IV:

1 - e
2 - f
3 - b
4 - a
5 - c
6 - d

XV:

1 - d
2 - a
3 - b
4 - f
5 - e
6 - c

XVI:

1: visit
2: like
3: is having
4: is riding
5: go
6: watch
7: are playing
8: are speaking
9: play
10: does...do
11: don't understand
12: do...like

C:

I:

A: 

1: Good morning
2: How
3: you
4: fine
5: thank you
6: I'm fine

B:

1: This is
2: Hello

@long0805

III.

- She speaks English but she doesn't speak Frech.

- I understand Maths, but I don't understand Sciene.

- He helps me with Sciene, but he doesn't help me with Maths.

- I borrow books about English, but I don't borrow books about History.

- You play the guitar, but you can't play the piano.

IV.

1. e

2. d

3. b

4. a

5. c

6. f

XV.

1. d

2. a

3. b

4. f

5. e

6. c

XVI.

1. They often visit their parents in the holidays. ( simple present )

2. I really like cooking. ( simple present )

3. He couldn't speak on the phone because he has a shower. ( simple present )

4. Look at that man. He is riding a horse. ( present continuous )

5. We sometimes go to the cinema on Sunday. ( simple present )

6. I watch about three DVDs a week. ( simple present )

7. We are playing tennis now. ( present continuous )

8. Right now, we are speaking Frech. ( preset continuous )

9. I sometimes play the guitar in the band. ( simple present )

10. When is Susie usually does her homework. ( simple present )

11. I don't understand German. ( simple present )

12. Do they like chocolate ice cream. ( simple present )