When a person is curious about something, it means he is interested in it and wishes to know something about it．There is     wrong with curiosity in itself．Whether it is good or bad depends on what people are curious about．

Curiosity sometimes     be foolish or wrong．Some people with nothing to do are full of curiosity about what their neighbors are doing．They have a strong wish to know what they are bringing home or taking outside, or     they have come home so early or late． To be interested in these things is silly because it is none of their__   to know what their neigh-bours do or are doing． Such curiosity is not only foolish but also harmful． Most probably, it may lead to a small talk which often brings harm or disrespect to others, thus     （hurt）others' feelings．

However, there is a clever curiosity-the curiosity of wise men, who wonder at all the great things and try to find out all they can learn about them．Columbus could never have found America if he    （not be） curious． James Watt would not have made the steam engine     his curiosity about the rising of the kettle lid． All the discoveries in human history have     （make）as a result of curiosity, so the clever curiosity is never about      （important） things which have little or nothing to do with the happiness of       public．

由本国政府、股份公司和银行发行的代表信贷关系的债务凭证是股票。 （　　）