Answer:
In the Characteristics coloumn, write down what's usual for summer and winter in North America (climate, rain,...), but in the Cause coloumn, write down what causes that (for instance: there are cold winters because of surroudings of mountains, hot weather near the coast,.... somethings like that, you probably get it now. ) I'm not an American, so I can't fully help you with this.
Step-by-step explanation:
^^^