---You haven't lost the concert ticket, have you? --______. I know it is not easy to get another one at the moment, but nowhere can I find it.
Up to now, the program ______ thousands of children who would otherwise have died.
Mark needs to learn Chinese ______ his company is opening a branch in Beijing.
Paper money was in ____ use in China when Marco Polo visited the country in ____ thirteenth century.
----I’m sorry I made a mistake ! ----_______. Nobody is perfect .
--- You know Brad Pitt is already fifty. --- You are kidding.He doesn’t look __________ .