We can have ___ blue sky if we create ___ less polluted world.
---Joan, you are late again!---Sorry, I _______next time.
---Let’s go fishing if it _______this weekend.---But nobody knows if it _________.
The windows of the classroom ________ every day.
---________ is “Lucky 52”shown on CCTV-2”?---Every week.
---Is everyone here today?---No, Lily is absent. She with her mother _______ to Guangzhou to see the flower shows.