Final answer:
The sentence 'There were not enough beds ____________. ____________...I had to sleep on the floor.' is correctly completed by using 'so' and 'but', indicating consequence and contrast respectively.
Step-by-step explanation:
The correct answer to fill in the blanks in the sentence "There were not enough beds ____________. ____________...I had to sleep on the floor." is 'so' for the first blank and 'but' for the second blank. The correct sentence would then read: "There were not enough beds so but...I had to sleep on the floor." This use of 'so' indicates a consequence or result, while 'but' introduces a contrast or an unexpected outcome, which fits the context provided.