IPv6协议在（）与安全性方面优于IPv4。
A.核心交换
B.流量均衡
C.转发交换
D.地址空间
参考答案：D
考考你的记忆力，根据句意及首字母补全在本课中出现的单词。
1.It's great h_____!
2.It's a very i___ book.I like it very much.
3.Let's t____ the books.Mine is about Lei Feng.What about your book?
4.Most people don't have cows and chickens a___
5.I n_____ to show you my hobby.
纸草文书
