— What will you do tomorrow?— We’ll have a picnic if it ______ fine.

I _______my teacher since last year. I miss him very much.

---- Where is your uncle now? I haven’t seen him these days． ---- He _______to the earthquake area with his workmates．

—Have you mended your shoes, Bob？—Yes, I ____ them twenty minutes ago ．

---How often ___________ the Olympics _____________? ---Every four years.