Question

at 10.9 km below sea level, the deepest trench in the world is the ______ trench.
mariana
peru - chile
tonga
south sandwich

Explanation:

The Mariana Trench is the deepest part of the world's oceans. It is located in the western Pacific Ocean, to the east of the Mariana Islands. The Peru - Chile Trench is the second - longest trench in the world but not the deepest. The Tonga Trench is the second - deepest oceanic trench. The South Sandwich Trench is also not the deepest.

Answer:

Mariana