Although I often send e-mails to Tom, I have never seen him _____________. 

The room wants ___.

--- Why didn’t Mr. Smith arrive on time for the meeting?--- He must have been ________ on his way here in the traffic jam. 

A great deal of advanced science and technology has been ______ since China carried out the reform and opening policy.

The pain is gone after weeks of the operation, but the scar _____.