A. Hosts 2， 3， and 4 will receive the broadcast. 
B. Hosts 1， 2， 3， and 4 will receive the broadcast.
C. Host 2 and the Fa0/0 interface of R1 will receive the broadcast.
D. Hosts 1， 2 and the Fa0/0 interface of R1 will receive the broadcast. 
E. Hosts 1， 2， 3， 4 and interface Fa0/0 of R1 will receive the broadcast.
F. Hosts 2， 3， 4， and interfaces Fa0/0 and Fa0/1 of R1 will receive the broadcast.

A.(config-if)#authentication ppp chap fallback ppp
B.(config-if)#authentication ppp chap pap
C.(config-if)#ppp authentication chap pap
D.(config-if)#ppp authentication chap fallback ppp

A.Bandwidth,Delay,and MTU
B.Bandwidth
C.Bandwidth and MTU
D.Bandwidth , MTU,Reliability,Delay,and Load

A. forwards the received packet out the Serial0/0 interface
B. forwards a packet containing an EIGRP advertisement out the Serial0/1 interface 
C. forwards a packet containing an ICMP message out the FastEthernet0/0 interface
D. forwards a packet containing an ARP request out the FastEthernet0/1 interface

A.decreasing the number of collision domains
B.filtering frames based on MAC addresses
C.allowing simultaneous frame transmissions
D.increasing the size of broadcast domains
E.increasing the maximum length of UTP cabling between devices