Ответ:
+ they have got a bike
— they haven`t got a bike
? Have they got a bike ?
+She has a big cake
— She doesn`t have a big cake
? Does she have a big cake ?
+My sister has got a dog
— My sister hasn`t got a dog
? Has my sister got a dog?
+Children have toys
? Do children have toys?
— Children don`t have toys