--__do you go to the English club?--Once a week.
We will spend our summer holiday in Guilin, but we haven’t decided______________.
— When _________ you________ your teeth, Billy? —Just now.
When I was walking in the street, I saw a plane___________ over my head.
We ___________ when the teacher came in.
I will let you know about it as soon as I _________ the news.