In this task, you're given an input that contains two words, and your task is to predict the correct preposition that connects these two words. Predict the preposition that explicitly conveys both words' meaning, e.g., Word1: king 
 Word2: fort: "king of fort". Possible prepositions are: "of", "on", "in", "for", "from", "about", and "with".

Let me give you an example: Word1: story 
 Word2: pearl
The answer to this example can be: of
Here is why: The preposition correctly connects two words turning it into the sentence 'story of pearl'.

OK. solve this:
Word1: service 
 Word2: customer
Answer:
for