Есть тут какой добрый человек, который поможет с английским?

Exercise 1    some/any/a
Complete the sentences with some, any, or a.
Example
I don't have    any     brothers or sisters.

1 Would you like _a_ cup of tea?
2 You have _a_  lovely pictures on the walls!
3 Is there _some_  water in the fridge?
4 Can I have _some_ grapes, please?
5 I'd like _a _ hamburger and chips, please.
6 Do you want _a_ sandwich?
7 The shop doesn't have _any_ potatoes, peas, or bread.
8 There are _some_ eggs in the cupboard, but there isn't _any_ sugar.

Что тут неправильно? Если есть желание, помогите ещё кое с чем =)