помогите пожалуйста с англ:

1 Do we use plurals when there is only one thing?
yes/no

2 Do we use plurals when we think of things as a group?
yes/no/both

3 Which is correct?
He's got a sheep. / He's got sheep./ both

4 Do we use a and an with specific singular nouns?
yes / no

5 Do we use the with plural nouns when we are talking generally?
yes/no

6 Which is correct?
Today is 15th April. / Today is the 15th April. / both​