We have realised that ____ is much that can be done to help improve our environment.

_____ is the population of China? It is about 1,300,000,000.

I’d like an ice cream. Are you having ________,too?

—Have Mike and Tina sold out all of the English storybooks?---Yes,completely.____ is left.

29. I have been absent for nearly half a month. I can't afford ________ week.