The correct matches are:
Antarctica - Bentley Subglacial Trench, Ellsworth Mountains
Bentley Subglacial Trench is a very large trench in Mery Byrd Land in the southern part of Antarctica, while the Ellsworth Mountains are the highest mountain range on the frozen continent, reaching heights of almost 4,900 meters.
Australia - Western Plateau, Gulf of Carpentaria
The Western Plateau, also known as the Australian Shield, is the oldest part of the Australian continent, while the Gulf of Carpentaria is a very large gulf located north of the country, connecting Australia with the Southeast Asian islands.
New Zealand - Christchurch, South Island
Christchurch is the largest city in the South Island of New Zealand, while the South Island itself is one of the two major islands that make up the country of New Zealand.