Final answer:
The appropriate words to complete the sentence are: amateurs and variable. Ski pistes for amateurs have variable snow density.
Step-by-step explanation:
The appropriate words to complete the sentence are: amateurs and variable.
Ski pistes for amateurs have variable snow density.
Amateurs refer to inexperienced skiers who are not experts or professionals. The snow density on ski pistes for amateurs can vary, meaning it is not consistent.