What is Big brother Big sisters? 
human
Big brother and big sister are programs broadcast on the cable network, MTV. 
assistant
Are you sure? 
human
I'm positive!
assistant
What is Big brother Big sisters? 
human
Big brother and big sister are programs broadcast on the cable network, MTV. 
assistant
Are you sure? 
human
Yes, absolutely.  Big brother and big sister are well-known television programs.
assistant