简叙硝化反应的主要危险性。
弯曲件常见的缺陷有哪些？
（）means the sufficiency of a vessel in materials，construction，equipment，crew，and outfit for the trade or service in which it is employed. ["Seaworthiness","Cargo-worthiness","Readiness","Proficiency"]
什么叫"界域语"，它在人际交往中有哪些要求？
有毒品对人体的危害有哪些？
简述隐藏新棘虫的生活史。
