Instructions: 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.
Input: a historian has stated that " it was quinine 's efficacy that gave colonists fresh opportunities to swarm into the gold coast , nigeria and other parts of west africa ".
Output:
a historian said , " it was quinine 's efficacy that gave colonists fresh opportunities to swarm into the gold coast , nigeria , and other parts of west africa ..