Here are the suitable prepositions for each blank:

1. A. more
2. B. more slowly
3. C. quicker
4. A. stronger
5. A. more convenient

So the completed sentences would read:

1. Medical help is **more** easily obtained in towns than in remote areas.
2. She walks **more slowly** than other people.
3. The girl seems to be **quicker** than we thought.
4. Today the wind is blowing **stronger** than it did last night.
5. Is living in the city **more convenient** than living in the countryside?