—What did you do on Earth Day this year?—We _____ a show to spread the message about protecting the environment.
E-mail, as well as telephones, _____ an important part in daily communication.
The water will be further polluted unless some measures______.
---Excuse me, sir, is this seat taken? ---_______.
--- Do you think Bob will attend the meeting this afternoon? --- ______.
The committee asked for these suggestions to be ______ on paper, so that they might study them further.