Answer:
11. Mrs. Santos offered bus service FOR there were many enrolled in summer activities.
12. Their lot has been baren for many years, SO
they planted fruit bearing trees on it.
13. The owners dug up well, FOR water is scarce these days.
14. SINCE i can't hear you well, can you find another spot with a better signal?
15. Can u state that again BECAUSE I am quite confused?
Explanation:
Underlined sentence = problem
Not underlined sentence = solution
Caps lock word = conjunction