Final answer:
Markings are not always accurate when using a utility locate service to identify underground utilities.
Step-by-step explanation:
When using a utility locate service to identify underground utilities, the statement 'Markings are not always accurate' is true. Utility locate services use various methods like ground-penetrating radar, electromagnetic detection, and sonar to identify underground utilities. However, there can still be errors or inconsistencies in the markings due to factors such as outdated records, inaccurate utility maps, or changes made after the original mapping.