各族烃类的裂解反应难易顺序为？
参考答案：
正烷烃>异烷烃>环烷烃（六碳环>五碳环）>芳烃
生物生活环境中的水、温度、空气等因素，是影响生物生存的______因素．
Little about her own safety when trying to save the poor blind man, though she was in great danger herself.
A．did Rose care
B．Rose did care
C．Rose does care
D．does Rose care
