已知苯与一卤代烷在催化剂作用下可生成苯的同系物（x= Cl或 Br 或I） 
在催化剂存在下，由苯和下列各组物质合成乙苯最好应选用的是
| A．CH3CH3和I2 | B．CH2=CH2和HCl |
| C．CH2=CH2和Cl2 | D．CH3CH3和HCl |
相关试题
Encourage your children to try new things, but try not to ___ them too hard.
| A．draw | B．strike | C．rush | D．push |
The computer was used in teaching. As a result, not only__________, but students became more interested in the lessons. 
| A．saved was teachers’ energy | B．was teachers’ energy saved |
C．teachers’ energy was saved | D．was saved teachers’ energy |
The children all turned ____ the famous actress as she entered the classroom. 
| A．looked at | B．to look at |
C．to looking at | D．look at |
Edward, you play so well. But I ______ you played the piano. 
| A．didn’t know | B．hadn’t known |
C．don’t know | D．haven’t known |
粤公网安备 44130202000953号