1. The problem asks for the temperatures in two cities, Berlin and Paris, based on thermometer readings. 2. Each thermometer scale ranges from -5 to 5 degrees, with zero in the middle. 3. Berlin's thermometer shows the red mercury level at -4, which means the temperature is $-4$ degrees. 4. Paris's thermometer shows the red mercury level at -3, which means the temperature is $-3$ degrees. 5. Negative numbers indicate temperatures below zero, which is common in cold weather. 6. Therefore, the temperature in Berlin is $-4$ degrees and in Paris is $-3$ degrees. Final answer: - Berlin: $-4$ degrees - Paris: $-3$ degrees