Решение:
- May I have some milk, please? Of course, there is a lot of milk left in the fridge. (Молоко - неисчисляемое, говорим о большом количестве).
- May I take some of the lemon sweets, please? Yes, but I'm afraid there aren't many left. (Сладости - исчисляемое, отрицание, говорим о малом количестве).
- Can I have a cup of tea, please? Of course, there are a lot of teabags in the cupboard. (Пакетики чая - исчисляемое, говорим о большом количестве).
Ответ: a lot of, many, a lot of