Как верно ответить ?1 How oftena) are you going to Londonb)do

Как верно ответить ?
1 How often
a) are you going to London
b)do you go to London
2 Should we stayand help them?
a) I think you would not.
b) I think you need not.
3 Have you ever
a) were there befor ?
b) been there befor ?
4 Are you used
a) to take pictures ?
b) to taking pictures ?