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.
(1) would be the only singular number. zero is neither singular or plural. there would be possibilities of having more than 1 answer in that case, so it is plural in the sentence.