Pupils seem to regard the new and the middle-standing teachers as being more______ than the veteran teachers.

A．an effort to protect an endangered marine species
B．the civilian use of a military detection system
C．the exposure of a U.S. Navy top-secret weapon
D．a new way to look into the behavior of blue whales

A．It is now partly accessible to civilian scientists
B．It has been replaced by a more advanced system
C．It became useless to the military after the cold war
D．It is indispensable in protecting endangered species