_____around the Water Cube, we were then taken to see the Bird’s Nest for the 2008 Olympic Games.
| A．Having shown | B．To be shown | C．Having been shown | D．To show |
You look so tired tonight. It is high time you_________.
| A．went to bed | B．went to sleep | C．go to bed | D．to sleep |
--I don't think we have met before.
--Yes, once at a party, but we___________.
| A．weren't introduced | B．didn't introduce |
| C．haven't introduced | D．were not introducing |
Our new house is very___________ for me as I can get to the office in five minutes
| A．convenient | B．comfortable | C．natural | D．helpful |
--I can't find Mr. Smith.
--It was in the hotel___________ he stayed.
| A．that | B．where | C．which | D．since |
Scientists say it may be five or ten years___________ it is possible to test this medicine on human patients.
| A．since | B．before | C．after | D．when |