Final answer:
The best method for keeping flies out can involve plastic door strips, but it is not universally the best solution for every facility or situation. A combination of methods customized to the facility's needs is typically more effective.
Step-by-step explanation:
The statement that the best way to keep flies out of a facility is to install plastic door strips can be considered false. While plastic door strips are one effective method for preventing flies from entering a facility, it is not universally the best method for all situations. Integrating multiple methods such as maintaining cleanliness, using air curtains, and implementing proper waste disposal practices in combination with plastic strips tends to be more effective. Additionally, factors like the type of facility, location, and the specific fly problem should be considered when deciding on the best fly control strategy.