Решение:
Заполняем пропуски подходящими притяжательными местоимениями.
- This is my book. What is --- name? (Its)
- John is my friend. --- sister is nice. (His)
- Mary is my friend. --- brother is nice. (Her)
- This is my cat. --- tail is long. (Its)
- This is your dog. --- tail is short. (Its)
- These are my keys. --- are on the table. (They are, но если нужно одно слово, то My)
Ответ: Its, His, Her, Its, Its, My.