Final answer:
The Single Intradermal Comparative Cervical Tuberculin (SICCT) test, used to screen for bovine tuberculosis in cattle, uses two injection sites.
Step-by-step explanation:
In the Single Intradermal Comparative Cervical Tuberculin (SICCT) test, two injection sites are selected on the animal. The SICCT test, also known as the tuberculin skin test, is used primarily in cattle to screen for bovine tuberculosis. The test involves injecting two types of tuberculin into separate sites on the animal's neck: one with avian tuberculin and another with bovine tuberculin. The animal's reaction to these injections is monitored to determine if there is a significant immune response indicating the presence of tuberculosis.