Meeting my uncle after all these years was an unforgettable moment, ____ I will always treasure.
| A．that | B．one | C．it | D．what |
We should do more such exercise in the future, I think, __________ we did yesterday.
| A．as | B．like | C．about | D．that |
This photo of mine was taken __________ stood the famous twin-tower before the 9.11 event.
| A．which | B．in which | C．where | D．there |
Though they met for the first time, they talked __________ they were good friends.
| A．even if | B．as if | C．even though | D．if only |
The medicine works more effectively __________ you drink some hot water after taking it.
| A．as | B．until | C．although | D．if |
It will be a long time __________ we finally solve the problem of pollution.
| A．before | B．since | C．when | D．Until |