请根据句子意思，选用适当词或用所给词的适当形式填空。

11. Because of the lack of the ______ （motivate）to study, he failed to pass the final exams.

12. The patient was quite beyond the possibility of ______（recover）.

13. Only by ______（acquire）a good knowledge of English can you do international business successfully.

14. Diamond necklaces and rings had been ______ (beauty) arranged on a background of black velvet.

15. However, I lost sight of Wang Ping when we reached ______ looked like a large market.

16. ______ rushed a tiger from among the bushes. As a result, a tourist was scared to death.

17. Unless ______(change), this law will make life difficult for farmers.

18. In China, especially in Shanghai, there was a time ______ many senior students wanted to study abroad.

19. Believe it or not, there is no such thing ______ standard English.

20. --- I saw no more than one motor car in that shop. Will you go and buy it?

--- No, I’d rather find ______ in other shops.