To live a low-carbon life , we must try to save _____ energy and produce ____ carbon .
I think you should tell your partner how ______ popcorn.
---May I have ______ piece of bread with butter? I’m not full. ---Certainly. Here you are.
---______will you be back to the office? ---In half an hour.
It’s impossible for us ______ robots like humans now.
There ______ a concert in the gym sometime next week.