6 . 根据句意，选择单词或短语并以其适当形式填空。

concern, doubt, admit, transport, reward, rescue, present, charge, fight, quality

1. There is no ________ that the search for those lost cultural relics will continue.
2. The air pollution is more and more serious at ________.
3. Sun Yingsha practised hard every day in order to be ________ as a competitor in the Olympic Games.
4. Who will take ________ of the company after the manager retires?
5. Nelson Mandela devoted his whole life to ________ for the freedom of the black.
6. John wanted to give 100 yuan as a ________ to the taxi driver who had found his wallet.
7. Ten fishermen were saved in a difficult sea ________.
8. What kind of ________ do you prefer to use: bus or train?
9. Our products of high ________ sell well in Britain.
10. As far as I am ________, you can do what you like.