许多基团可通过向得自胶的重氮盐作亲核取代而加以导入.Many groups can be added by nucleophilic substitution on a diazonium salt.大多数连于芳核能被直接取代的基团仅限于重氮盐.Most direct substitution of groups bound to an aromatic nucleus is limited to diazonium salts....
Bessie, resplendent in royal blue velvet, was hovering beside the table.贝茜身穿华丽的深蓝色天鹅绒衣服，在桌旁徘徊。She was wearing a white ruffled blouse and a blue velvet skirt.她穿着一件有花边的白色上衣和一条蓝色天鹅绒裙子。The curtains and the coverlet of the be...
The maintenance management among them is the important subsystem of equipment control.其中的维修管理是设备管理的重要子系统.The interlocked multi - system applies a switching - screen technique that effectively interconnects each subsystem...
他通过严格控制公共开支保持预算平衡。He balanced his budgets by rigid control over public expenditure.我部门对维持低水平开支有浓厚兴趣。My department had a healthy interest in keeping expenses down.该项目的开支是否真的合理还未可知。It is questionable whether the expenditur...