He knew that
| P : | and then to save himself |
| Q : | was to save all the lives |
| R : | entrusted to his care |
| S : | the duty of a captain |
PQRS
SQRP
SPRQ
QSRP
Next Question
Since the beginning of history | P : | have managed to catch |
| Q : | the Eskimos and Red Indians |
| R : | by a very difficulty method |
| S : | a few specimens of this aquatic animal |