In the following passage, some words have been deleted. Read the passage carefully and select the most appropriate option to fill in each blank.

Elephant Island's name is attributed to (1) ______ its elephant head-like ppearance and the sighting of elephant seals (2) ______ Captain George Powell in 1821, one of the 3) ______ sightings. (4) ______, in Russia it is still known under the name (5) ______ by ts discoverers in 1821 - Mordvinova Island.