Поставить вопросы(общий,специальный, вопрос к подлежащему,альтернативный) they usually go to the lake in summer

They usually go to the lake in summer

Do they usually go to the lake in summer?
Who usually goes to the lake in summer?
Do they usually go to the lake or to the river in summer?
What do they usually do in summer?
They usually go to the lake in summer, don't they?