Trees can stop the sand _____ towards the rich farmland in the south.
--- You can’t ____what a terrible weekend I had. I had a bad cold.--- I’m sorry to hear that.
--- What about going hiking this weekend?---Sounds good. The weather is _____.
There will be _____ pollution this year than last year.
---Where’s Mary? I didn’t see her this week.--- I didn’t see her, _____.
---What’s happening?--- There was ____ accident just now.