It is said that some of the relief work has been done by             (志愿者).

根据下列句子及所给汉语注释，在下面的横线上写出空缺处各单词的正确形式（每空仅填一词）。

1．It is _________（犯罪）to lie and cheat to get what one wants．

2．Even an experienced teacher doesn't know how to deal with the _______（令人烦恼） problem．

3．You shouldn't show _________（仁慈） to this kind of man．

4．My teacher often tells us that we shouldn't be too ________（贪婪）for power and money．

5．The writer has visited more than one hundred book-stores in order to ___________（促销）his new book．

6．His ears are highly________（敏感） to any unusual sound in the machine．

7．It is reported that this type of plane can fly at an _________（高度） of 30,000 feet．

8．Tell me your _________（背景）now that you want to apply for the job．

9．There are still groups fighting against _________（偏见） and for equal right of people．

10．It is said that some of the relief work has been done by             （志愿者）．