Here are the sentences completed with the correct comparative forms:

1. Cattle usually cross over the road here, so you should drive more **carefully**.
2. Life in cities is **faster** and **more convenient** than that in the countryside.
3. Farmers often have to start a day **earlier** than city dwellers.
4. I think people in the countryside are **friendlier** than those in the city.
5. Living in this small town is **more peaceful** than I expected.
6. Houses in cities are much **taller** than those in the countryside.
7. Air pollution in our city is much **worse** than it used to be.
8. The modern harvest machine is **more effective** than the old one.
9. The road in this small town is crowded and narrow, so you had better drive a bit **slower**.