Read the following paragraph and identify the topic sentence:
Driving in winter can be less problematic if you take a few simple precautionary steps. Firstly, if you are planning to drive on snowy, icy roads, put on snow tires. Secondly, make sure you have enough antifreeze in your radiator. Next, add anti freeze to your windshield washer fluid to avoid the fluid freezing and breaking the container. Finally, carry tire chains, a spray-can to unfreeze door locks, and a windshield scraper in your car when driving in cold weather.