Which command generates a BERT test pattern of all zeros on T1 number 1 for ten minutes?（）

单项选择题Which command generates a BERT test pattern of alternating ones and zeros on T1 number 1 for one minute?（）

A.A
B.B
C.C
D.D

单项选择题Which command displays the results of a loopback test you executed on a CT3 line module in slot 5, port 0, t1 number 4?（）

A.A
B.B
C.C
D.D

单项选择题Which command is used on the local router to invoke a loopback mode on a remote ERX Edge Router?（）

A.A
B.B
C.C
D.D

单项选择题Which command prompts an ERX Edge Router to go into a loopback mode on T1 number 1 when a command is received from a remote ERX Edge Router?（）

A.A
B.B
C.C
D.D

单项选择题Which control expression must be the last line in all macros?（）

A.A
B.B
C.C
D.D