Taking a news photograph has two obvious characters : actuality and instancy . The former embodies objectivity and reality . But the latter is a basic character of taking a news photograph and is the chief content of this investigation too .

新闻摄影有纪实性和瞬间性两个突出特征，纪实性是客观和真实的体现，瞬间性则是新闻摄影的基本特征也是本文的主要研究内容。

Given the severe methane disaster situation in china 's coal mines , the reasons of the disasters are anaylzed with safety science & technology and management science , and the instancy and necessity of strengthening basie research on safety science is also put fonvard .

结合我国煤矿瓦斯灾害的严峻现状,从安全科学技术与安全管理的角度分析了煤矿瓦斯灾害多发的原因,提出了今后加强安全科学基础研究的迫切性和必要性。