Job Outlook. Excellent. Respiratory therapists provide care and treatment for patients suffering from breathing and cardiopulmonary difficulties. They may also provide emergency medical care for patients who have experienced asphyxiation, heart attacks, or shock.
0 is a number alone or not. if you put 0 by itself its both a number and a digit.
A digit is an element of a set that, taken as a whole, comprises a system of numeration. Thus, a digit is a number in a specific context. In the decimal (base-10) Arabic numbering system, the digits are the elements of the set {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}. In the binary number system, the digits are the elements of the set {0, 1}. This system is used by computers because the two digits can represent the logic low and high states. The term binary digit is compressed to  bit  in computer parlance.