The fourth factor is something that humans needed to sustain life. Without having to rely on other facilities, such as computers. Auto electrical, telephone, etc. by this factor cannot be missing. When worn out may affect your lifestyle.
Four factors is essential to human life. Without other amenities. Such as computers, cars, electricity, telephone, etc., factors which can not be without. When absent, then it may affect their lives.
The basic is the human things necessary to live. Without other amenities, such as a computer, automotive, electrical, telephone, etc. these factors also can not be broken. When worn may affect lifestyle.