17. Your handwriting is now (good) than it was last year; but still it is not so (good) as Nick's handwriting. Nick has a (good) handwriting than you. And of course Nellie has the (good) handwriting of all.

Краткое пояснение:

Пошаговое решение:

1. Определяем прилагательное: good.
2. Для первого случая ('than it was last year') используем сравнительную степень: better.
3. Для второго случая ('not so (good) as Nick's handwriting') используем исходную форму: good.
4. Для третьего случая ('(good) handwriting than you') используем сравнительную степень: better.
5. Для четвертого случая ('the (good) handwriting of all') используем превосходную степень: best.

Ответ: better, good, better, best