If  we ___________some measures, we might have prevented the environmental pollution.

. Our TV sets sell well, but ten years ago no one could have imagined such a big share in the market that they ____.

Our family       made up of six people, and all       music.

---Now, have you finished your work yet?--- Yes, I _______ it when you came.

—Jane and July are here. Did I introduce them to you?—No，you didn’t. I’ve seen them，but we__________.