—People often don't appreciate what they have, do they?
—No, _________ they lose it.
| A．if | B．after | C．until | D．when |
---- My leg hurts a lot
----You'd better go to the doctor and have it ____.
| A．examined | B．being examined | C．to be examined | D．examining |
Mary went to the box office at lunch time, but all the tickets __________ out.
| A．would sell | B．had been sold | C．have been sold | D．was selling |
News came from the office __________ Wang Lin had been admitted to Beijing University.
| A．which | B．what | C．that | D．where |
Whenever I met her, __________ was very often, she greeted me with a sweet smile.
| A．who | B．which | C．when | D．since |
Peter was so excited __________ he received an invitation from his friend to visit them.
| A．where | B．that | C．why | D．when |