常见的核磁共振氢谱图的内标试剂(d = 0)为()
A. TMS
B. DMSO
C. THF
DME
下列化合物中不能发生Friedel-Crafts的是()
A. 硝基苯
B. 苯
C. 甲苯
D. 氯苯
International Factoring can increase liquidity to finance working capital and enhance the exporter’s borrowing potential. ( )
The offer for 3,000 bicycles made by A&C Company remains ____ for a week.
A. firm
B. good
C. open