A dog robot could help ____ the room.
---How many Chinese astronauts ______ into space since 2003?----Twelve , including two women.
---Who helped you clean the classroom yesterday?---_______. I did it all by myself.
I remember ______ the math problem ______.But I can’t remember it’s answer.
It’s said that _____ of the water around the world _____ polluted.
---May I have a look at your plan for the robot ?----Sorry ,I’ve _____ it at home .