III.
$\text{21. succeed}$
$\text{22. friendly}$
$\text{23. better}$
$\text{24. pronunciation}$
$\text{25. improvement}$
$\text{26. participational}$
$\text{28. proud}$
$\text{29. importance}$
$\text{30. easily}$
IV.
$\text{a. What will you do if you are in my situation?}$
$\text{b, have not seen}$
$\text{c, started ; was}$
$\text{d, was singing}$