The main purpose of Paragraph 2 is to ______.

A．answer an objection that some readers may raise to Paragraph 1

B．guard against the possibility that you have read Paragraph 1

C．contradict the idea of Paragraph 1

D．show more optimistic than Paragraph 1

聚会用的烟火属于（）类违禁物品。

A.可以用来致伤的尖状或有刀刃的物体。

B.可以用来致伤的钝头物体

C.对旅客和机组的健康或航空器和财产的安全产生危险的爆炸或高度易燃的物质

D.对旅客和机组的健康或航空器和财产的安全产生危险的化学和有毒物质