请教两个问题，给出原因，好吗？多谢！
1. a hosta in the sale department cant connect to the hostb in management department. choose the reason! routera(e0)-----------------------(e0)routerb 192.168.23.1 192.168.21.5 | | | | | | hosta hostb 192.168.23.2 192.168.21.2255.255.255.240.0 255.255.255.240
a. the routerb inteface's ip addresss.
b. hosta's bad ip address
c.hostb's badd ip address
d.bad broadcast address
e.the routera interface's ip addresss.
Answer:c
2。 Which wan equipment provides the best quality and quantity about data and signal? a. isdn
b. atm
c. fddi
d. token ring
Answer :B
