TASK DEFINITION: In this task, you're given a sentence and your task is to generate a simplified sentence that focuses on lexical paraphrasing from the original sentence given in the input.
PROBLEM: an oratorio is a large musical composition including an orchestra , a choir , and soloists.

SOLUTION: an oratorio combines an orchestra , choir , and soloists into a large musical composition.

PROBLEM: it is one of the nine species of leaf-eating kangaroos identified in fossils found in the naracoorte caves national park.

SOLUTION: this is one of nine types of leaf eating kangaroos found in the naracoorte cave national park fossils.

PROBLEM: the amazon basin is the part of south america drained by the amazon river and its tributaries.

SOLUTION:
the amazon basin is part of south america drained by the amazon river and tributaries.