Future Simple vs. to be going to

Ben ... meet his friends after school today at 7 o'clock.

It's cold here. I ... the window.

I think he ... buy a new computer in 2 months.

In 2057 they ..... celebrate their birthdays on the Moon.

I promise I ..... finish work in three hours.

I bought lots of vegetables on Monday. I ... make salad

We are hungry. I ... make some sandwiches.

I am thirsty. I ... have some orange juice.

In the evening we ... stay at home.

I tnink they .....go to the party tomorrow afternoon.

I.... cook a tasty cake for my friend.

OK, Mum. I ... buy milk for supper.