下列反应的生成物为纯净物的是[ ]
A．甲烷和氯气光照
B．氯乙烯的加聚
C．乙烯和溴水加成
D．丙烯和HCl加成
答案：C
Putting in a new window will ______ cutting away part of the roof.
A．contain
B．comprise
C．include
D．involve
苯胺—甲醛树脂( ) A．23 B．24 C．25 D．26
