The trachea, pharynx, diaphragm and lungs are all that belong to respiratory system.

The trachea, pharynx, diaphragm and lungs are all parts that belong to the respiratory system.

Explanation:

The trachea is a thin layer of tissue that prevents food and liquids from entering the pharynx. It is a tube by means of which air passes from and to the lungs. It is also called the windpipe.

The pharynx is the part of a throat behind the mouth. Given its anatomical structure, it is part of the respiratory and digestive systems. Air passes through the pharynx on its way to the lungs.

The diaphragm is a muscle the main function of which is to contract and flatten when a person inhales (air is pulled into the lungs) and when a person exhales, air is pushed out of the lungs.

The lungs are the organs which transport oxygen to body cells. The main function of lungs is the process of gas exchange called respiration or breathing.  

the organs

Explanation:

The respiratory system is divided into two main components: