[问答题] 简叙硝化反应的主要危险性。

拜访的礼仪应注意哪些方面？ 冲压生产中减少回弹的立法和措施有哪些？ A mortgagee does not acquire a right to the freight（）he has taken actual or constructive possession of the ship. ["where","if","and","unle"] （）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"] 冲压生产中（变）成形工序中常见的缺陷主要有哪些？ 简叙硝化反应的主要危险性。