试题(55)、(56) 下面的D类地址中，可用于本地子网作为组播地址分配的是____

学习隋唐史后，四位同学作了主题演讲，你认为能准确地概括这段历史的基本特征的[ ]

A．文明初露曙光

B．分裂奔向统一

C．繁荣与开放

D．封建国家陷入危机

I still remember the morning. My father suddenly wake me up at about 5 and the sky was still gray. I jumped out bed surprised and extreme happy, for we were going to get a book! When we drove to the bookstore, many people were already waiting there. We waited for our turn at about 8:30. I was overjoyed when I got a book, not only because of the book themselves, but also of the love from my father. Never before had I felt such a love from him, because of my father, I believed then, had always been busy with his own work. That was “Harry Potter” that helped I feel the deep love from my parents!

下图是各物质的反应关系图:已知A和E都是黄色粉末，A常用为呼吸面具的供氧剂，E在空气中燃烧火焰为淡蓝色，F有刺激性气味且有漂白性常被不法商人用来漂白银耳、腐竹等，H具有很强腐蚀性。请据此回答下列问题:

(1) 写出下列各物质的化学式: A.__________  F_________

(2)写出图中编号的化学方程式: ①____________________ ②______________

5岁患儿有预激综合征，该患儿最常并发心律失常是：（）

A.室性心动过速

B.第一度房室传导阻滞

C.心房颤动

D.完全性房室传导阻滞

E.阵发性室上性心动过速

5，7，11，17，( )

A．25

B．24

C．19

D．38