We can't avoid negative thoughts，but we should make it a habit to replace each negative thought with a positive________．

Haze (雾霾)appears around us. Let’s do ________ helpful to protect the environment.

--You know Mr. Green has been ill for days? --Yes, I wonder if he is ______ better now. 

We enjoyed the trip and we hope to visit it ________.

Some people think _______about their rights than they do about their responsibilities.