Exercise:

1.

Exercise:

2.

Exercise:

3.

Exercise:

4.

Exercise:

5.

Exercise:

6.

Exercise:

7.

Exercise:

8.

Exercise:

9.

Exercise:

10.

Exercise:

11.

Exercise:

12.

Exercise:

13.

Exercise:

14.

Exercise:

15.

Exercise:

16.

Exercise:

17a.

Exercise:

17b.

Exercise:

18a.

Exercise:

18b.

Exercise:

19.

Exercise:

20.

Exercise:

21a.

Exercise:

21b.

Exercise:

21c.