III:

1. The food was too hot for us to eat.

2. I didn't have enough money to buy a taxi.

3. Sarah is too busy to take a day off.

4. It's too wet to have a picnic.

5. The piano was too heavy for everybody to move.

6. The coat isn't warm enough for me to wear in winter.

7. I haven't got enough chairs for all my guests to sit on.

8. The situation is too complicated to explain the situation.

9. This sofa isn't wide enough for three people to sit on.

10. I had too much equipment to carry.

11. The wall was too high for us to climb over.

12. Natasha is good enough to be a professional musician.

13. The water isn't clean enough to swim in.

14. Some things are too small for us to see without a microscope.

15. He wasn't experienced enough to get the job.

IV:

1 such

2 so

3 such a

4 such

5 such a

6 such

7 so - such 

8 so

9 such a

10 so

11 such

12 so

=>
III/
1. The food was too hot for us to eat.
2. I didn't have enough money to take a taxi.
3. Sarah is too buys to take a day off.
4. The weather isn't dry enough for a picnic to be nice.
5. The piano was too heavy to be moved./ The piano was too heavy for anyone to move.
6.  This coat isn't warm enough for me to wear in water.
7. I haven't got enough chairs for all my guests.
8. It's too complicated for me to explain the situation.
9. It isn't wide enough for three people to sit on this so far.
10. I had too much equipment to carry.
11. It was too high for us to climb over the wall.
12. She is good enough to be a professional musician.
13. The water isn't clean enough for us to swim in.
14. They are too small for you to see some things without a microscope.
15. He wasn't experienced enough to get the job.

IV/
1. such
2. so
3. such a
4. such
5. such a
6. so 
7. so/such
8. so
9. such a
10. such
11. such
12. so