Our government has tried many ways to _________ the smog haze(雾霾) problem. Maybe we’ll have a clearer sky in the near future.

up, Maria! You can also enjoy ___ you have been dreaming of, if you don’t lose heart.

My brother suggested he and I be taken toan amusement park this weekend, and we were glad to know that our busy parentsdid not ___ to the plan.

I think the Grand Canyon is unusual natural wonder of the world.

There is no______ in trying to talk him into joining us. He enjoys being alone.