Focusing on what is being said, repeating what you heard, asking a speaker to expand or clarify, looking for non-verbal signals, and listening for requests are principles of listening.

Active listening.

Explanation: This is a technique or skill that can be developed. It basically means that you are completely paying attention to the other person instead of being a passive listener. To demonstrate that you are actually paying attention, you can repeat details that you already heard, make questions or ask the speaker to clarify. With these actions the speaker will know that you are focused on the conversation.  

the correct answer is the following is a list of inventions made in the medieval islamic world, especially during the "islamic golden age" (8th to 13th centuries),[1][2] as well as the late medieval period, especially in the emirate of granada and the ottoman empire.

science and technology in the islamic world adopted and preserved knowledge and technologies from contemporary and earlier civilizations, including persia, india, china, and greece-roman antiquity, while making a number of improvements and innovations.