商业上采用的以镍作催化剂的氢化有两种.Commercially two main types of hydrogenations are carried out with Nickel catalyst.抑制剂和促进剂能影响氢化速率.Inhibitors and promoters may affect the rate of oxxidution.用六氢化邻苯二酸酐加入到邻苯二酸酐中,可使其放热反应减慢.Exothermic reac...
Name six perennials and six annuals suitable for indoor flower arrangement.列出多年生及一年生花朵各六种,它们必须是适合插花的.Herbage can be divided into three categories : annuals , biennials, and perennials.草本植物可分成一年生 、 二年生和多年生.Perennials like...
If the foundations are flawed the house will come tumbling down.如果地基不牢，房子将会倒塌。A canny investor would need to predict when the dollar will once more start tumbling...精明的投资者需要预计到美元何时会再次大跌。...the aromatic pines and tumbling...
This state of discontent and disillusionment created a real crisis for the Republic.怨声载道和理想破灭的现状给共和国造成了极为严重的危机.Poverty, disillusionment, disease could not still his music.贫困 、 幻灭疾病都不能停息他的音乐.You must be prepared for disil...