TASK DEFINITION: In this task, we ask you to rewrite a sentence in simple English without changing its general meaning. Essentially, you want to make the sentence easier to read by using simpler words, utilizing more straightforward sentence structures, and omitting non-essential information etc.
PROBLEM: The Royal Institute of International Affairs , commonly known as Chatham House , is a not-for-profit and non-governmental organisation based in London whose mission is to analyse and promote the understanding of major international issues and current affairs .

SOLUTION: Chatham House , also known as the Royal Institute of International Affairs , is a London think tank .

PROBLEM: The Congressional Record is the official record of the proceedings and debates of the United States Congress , published by the United States Government Publishing Office and issued when Congress is in session .

SOLUTION: The Congressional Record is the official record of the United States Congress .

PROBLEM: Over-the-counter ( OTC ) drugs are medicines sold directly to a consumer without a prescription from a healthcare professional , as opposed to prescription drugs , which may be sold only to consumers possessing a valid prescription .

SOLUTION:
Over-the-counter drugs ( OTC ) are drugs that do not need a prescription to be bought .