how was your weekend? —- Great! It was my grandfather’s _______ birthday. We enjoyed ourselves.

_____ of the water _____ polluted. We must try to protect our environment.

We will have a _____ holiday after the exam .

______ does your sister walk her dog?— Once a day. [ ]

Jane, I can’t find Lucy in the classroom. —Oh, she ________ the piano in the music room.