I don’t quite understand what you said. Would you please give us ______example?
--- What’s the matter, Mary? You looked upset.--- I failed again in my math exam. I’m really sorry because I don’t want to ____ my parents down.
--- Do you have any plans for this weekend?--- I’m not sure. I _____ go climbing Mount Baoshi.
The world’s population is growing ______, and there is ____ land and water for growing rice.
Lincoln came from nothing, yet but he did ____ that changed the world.
---Why didn’t Sally play the violin at the concert last night?---She said that her hand hurt, but that was only a(n) _______. I saw her play tennis just now.