6) A. Darkly
7) Whitehall is C. the street in London
8) first conditional - If we lived in a town, life would be easier.
third conditional - If you had told me about the problem, I would have helped you.
second conditional - If it rains, we will not go to the picnic.
9) He should swim very well when he was young.
You could not leave your keys in the car.
You need a long rest.
10) Gerund - I remember having my birthday party.
Infinitive - Remember to bring you dictionary.